TS Inter 2nd Year

Students can go through TS Inter 2nd Year Chemistry Notes 13th Lesson Organic Compounds Containing Nitrogen will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 13th Lesson Organic Compounds Containing Nitrogen

→ Amines can be considered as derivatives of ammonia obtained by replacement of one, two or all the three hydrogen atoms by alkyl and / or aryl groups.

→ The amines are classified as primary (1°), secondary (2°) or tertiary (3°) amines. They are represented by the general formulas RNH2 (Primary amines), R₂NH or RNHR’ (Secondary amines) as R₃N or R NR’ R” or R₂ NR’ (Tertiary amines).

→ All the three types of amines behave as Lewis bases due to the presence of one unshared electron pair on nitrogen atom.

→ Amines are obtained from nitrocompounds, halides, amides, imides etc.

→ Primary and secondary amines are involved in intermolecular association due to inter- molecular hydrogen bonding. Tertiary amines have no intermolecular hydrogen bonding due to the absence of H-atom on nitrogen. Hence the boiling points of isomeric amines are in the order.
1° > 2° > 3°

→ The order of basicity of amines in the gaseous phase follows the order :
3° > 2° > 1° > NH₃

→ In aqueous solution the order of basicity of substituted amines is
(CH₃)₂ NH > CH₃ NH₂ > (CH₃)₃ N > NH₃
(C₂H₅)₂ NH > (C₂H₅)₃N > C₂H₅NH₂ > NH₃

→ Aliphatic and aromatic primary amines on heating with chloroform and ethanolic KOH form isocyanide or carbylamine which are foul smelling substances. Secondary and tertiary amines do not give this reaction.

→ Benzene sulphonyl chloride (C₆H₅.S0₂Cl) is known as Hinsberg’s reagent. It is used to distinguish between primary, secondary and tertiary amines and also to separate the amines from their mixture.

→ -NH₂ group is ortho and para directing and a powerful activating group in electrophilic substitution reactions of aniline.

→ Diazonium salts have the general formula
R N₂ X where R stands for an aryl group and X ion may be Cl, B̅r̅, HS̅O̅₄ , BF̅₄ etc.

→ Diazonium salts are very good intermediates for the introduction of – F, – Cl, – Br, – I, – CN, – OH, – NO₂ groups into the aromatic ring.

→ Alkyl cyanides are alkyl derivatives of hydrogen cyanide and isocyanides are isomers of alkyl cyanides.

→ Alkyl cyanides are usually obtained from alkyl halides, aldoximes and amides. Alkyl isocyanides are formed from alkyl halides by reacting with silver cyanide. Alkyl cyanides are used as intermediates in the multistep organic synthesis.

Students can go through TS Inter 2nd Year Chemistry Notes 12th Lesson Organic Compounds Containing C, H and O will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 12th Lesson Organic Compounds Containing C, H and O

→ An alcohol contains one or more hydroxyl (- OH) group(s) directly attached to carbon atom(s), of an aliphatic system. A phenol contains – OH group(s) directly attached to carbon atom(s) of an aromatic system.

→ Ethers are compounds formed by substituting the hydrogen atom of hydroxyl group of an alcohol or phenol by an alkyl or aryl, group.

→ Alcohols and phenols may be classified as mono-, di-, tri or polyhydric compounds depending on whether they contain one, two, three or many – OH groups respectively.

→ Primary (1°), Secondary (2°) and tertiary (3°) alcohols may be shown as given below:

→ In allylic alcohols, the – OH group is attached to an sp3 hybridised carbon next to the carbon-carbon double bond.
Ex : CH₂ = CH – CH₂OH (Allyl alcohol)

→ In benzylic alcohols, the – OH group is atta-ched to a sp3-hybridised carbon atom next to an aromatic ring.
Ex: C₆H₅CH₂OH (Benzyl alcohol)

→ In vinylic alcohols, the – OH group is bonded to a carbon-carbon double bond.
Ex: CH₂ = CH – OH (Vinyl alcohol)

→ Ethers are classified as

• Simple or sym-metrical and
• Mixed or unsymmetrical.

In simple ethers, the alkyl or aryl groups attached to the oxygen atom are the same.
Ex : C₂H₅OC₂H₅, Diethyl ether.
In mixed ethers, the two alkyl or aryl groups are different.
Ex: Anisole, C₆H₅OCH₃.

→ Cresols are substituted phenols having methyl groups in the ortho, meta or para positions.

→ Dihydroxy derivatives of benzene :

→ Alkenes react with water in the presence of acid to form alcohols. In unsymmetrical alkenes the addition of water takes place according to Markonikoff’s rule.

→ Alcohols are also prepared by hydro bora- tion – oxidation of alkenes. The addition of water to the alkene follows anti-Markoni- koff’s rule.

→ Aldehydes and ketones are reduced to the corresponding alcohols by addition of hydrogen in the presence of metal catalysts. However, many of the catalysts used (Pt, Pd, Ru, Rh) are relatively expensive and that other functional groups also react (C = C, – C = C – – NO₂, – C = NT).

→ Carboxylic acids are reduced to 10 alcohols in excellent yield by lithium aluminium hydride.

→ Alcohols are produced by the reaction of Grignard reagents with aldehydes and ketones. The reaction produces a 1 ° alcohol with methanal (formaldehyde), a 2° alcohol with other aldehydes and 3° alcohol with ketones.

→ Phenol is prepared from chloro benzene first by fusion with NaOH at 623 K and 320 atmospheres pressure, followed by acidification of the sodium phenoxide produced.

→ Diazonium salts are hydrolysed to phenols by warming with water or by treating with dilute acids.

→ Solubility of alcohols and phenols in water is due to their ability to form hydrogen bonds with water molecules.

→ Alcohols and phenols react with active metals such as Na, K and Al to yield corresponding alkoxides / phenoxides and hydrogen. Phenols react with NaOH to form sodium phenoxides.

→ In substituted phenols, the presence of electron withdrawing groups such as nitro group, enhances the acidic strength of phenol. On the other hand, electron releasing groups decrease the acid strength.

→ Lucas reagent (Cone. HCl and ZnCl is used to distinguish between primary, secondary and tertiary alcohols. At room temperature, tertiary alcohols react immediately with Lucas reagent producing turbidity in the reaction mixture, the secondary alcohols give turbidity within 5 to 10 minutes and the primary alcohols do not give turbidity at all at room temperature.

→ With Cone. HNOs, phenol is converted to 2, 4, 6 – trinitrophenol which is known as picric acid.

→ When phenol is treated with bromine water, a white precipitate of 2, 4, 6- tribromo phenol is formed.

→ Sodium phenoxide on reaction with carbon dioxide followed by acidification gives salicylic acid.

→ On treating phenol with chloroform in the presence of NaOH, a -CHO group is introduced at ortho position of the benzene ring. This reaction is called Reimer-Tiemann reaction.

→ Methanol, CH₃OH, is known as ‘wood spirit’. Methanol is produced by catalytic hydrogenation of carbon monoxide at high pressure and temperature in the presence of ZnO, Cr₂O₃ catalyst.

→ Ethanol, C₂H₅OH is obtained commercially by fermentation of sugars.

→ Ethoxy ethane (diethyl ether) is obtained when ethanol is dehydrated with Cone. H₂SO₄ at 413 K.

→ Williamson synthesis is an important method for the preparation of symmetrical and unsymmetrical ethers.

→ The C – O bond in ethers is polar and hence, ethers have a net dipole moment.

→ The boiling points of ethers resemble those of alkanes while their solubility is comparable to those of alcohols having the same molecular mass.

→ The alkoxy group (- OR) in alkyl ary ethers is ortho, para directing and activates the aromatic ring towards electrophilic substitution.

→ Aldehydes and ketones are the simplest and most important carbonyl compounds

→ Aldehydes and ketones are often called by their common names instead of IUPAC names.

→ The IUPAC names of open chain aliphatic aldehydes and ketones are derived from the names of the corresponding alkanes by replacing the ending – e with – al and – one respectively.

→ The carbonyl carbon atom is sp² – hybridised and forms three sigma (σ) bonds. The fourth valence electron of carbon remains in its p-orbital. This p-orbital forms a π – bond with oxygen by overlap with p-orbital of an oxygen.

→ Aldehydes and ketones are generally pre-pared by oxidation of primary and secondary alcohols respectively.

→ Ozonolysis of alkenes followed by reaction with zinc dust and water gives aldehydes, ketones or a mixture of both depending on the substitution pattern of the alkene.

→ Acyl chloride is hydrogenated over a catalyst, Pd over BaSO₄. This reaction is called Rosen-mund reduction.

→ Nitriles are reduced to corresponding ami¬nes with stannous chloride and HC/, which on hydrolysis give corresponding aldehydes. This reaction is called Stephen reaction.

→ Strong oxidising agents, for example potas-sium permanganate, oxidise toluene and its derivatives to benzoic acid.

→ Chromyl chloride, a mild oxidising agent, oxidises the methyl group of toluene to a chromium complex which on hydrolysis gives benzaldehyde. This reaction is called Etard reaction.

→ Side chain chlorination of toluene gives benzalchloride which on hydrolysis gives benzaldehyde.

→ Benzaldehyde and substituted benzaldehyde can be prepared by Guttermann-Koch reaction.

→ When benzene or its derivative is treated with carbon monoxide hydrogen chloride in the presence of anhydrous aluminium chloride or cuprous chloride, it gives benzaldehyde or substituted benzaldehyde.

→ When benzene or substituted benzene is treated with acid chloride in the presence of anhydrous AlCl3, it gives the corresponding ketone. This reaction is known as Friedel Crafts acylation.

→ Alkenes undergo electrophilic addition reactions whereas aldehydes and ketones undergo nucleophilic addition reactions.

→ Aromatic carboxylic acids can be prepared by vigorous oxidation of alkyl benzenes with chromic acid or acidic or alkaline KMnO₄. The side chain, irrespective of its length, is oxidised to – COOH.

→ Aldehydes and ketones undergo nucleophilic addition reactions with hydrogen cyanide, sodium bisulphite, Grignard reagents and alcohols. They also undergo addition- elimination reactions with ammonia and its derivatives.

→ Carboxylic acids have higher boiling points than aldehydes, ketones and alcohols of comparable molecular masses. This is due to more extensive association of carboxylic acid molecules through intermolecular hydrogen bonding.

→ Aldehydes and ketones are reduced to primary and secondary alcohols respectively by sodium borohydride (NaBH₄) or lithium aluminium hydride (Li AlH₄) as well as by catalytic hydrogenation.

→ Carboxylic acids are more acidic than phenols because the carboxylate ion is more stabilised than phenoxide ion.

→ Carboxylic acids on heating with sulphuric acid or P₂O₅ give corresponding anhydride. Thus acetic acid gives acetic anhydride (ethanoic anhydride) when heated with H₂SO₄ or P₂O₅.

→ The group of aldehydes and ketones is reduced to CH, group on treatment with Zinc-amalgam and concentrated HCl (Clemmensen reduction) or with hydrazine – followed by heating with NaOH or KOH in high boiling solvent like ethylene glycol (Wolff-Kishner reduction).

→ Carboxylic acids give esters when heated with alcohols or phenols in the presence of concentrated H₂SO₄ or HCl gas as catalyst.

→ Aldehydes are easily oxidised to carboxylic acids having the same number of carbon atoms. Ketones are generally oxidised under vigorous conditions to give a mixture of carboxylic acids having less number of carbon atoms than the parent ketone.

→ HVZ reaction – carboxylic acids having an α-hydrogen are halogenated at the α – position on treatment with chlorine (or) Bromine in the present of small amount of red phosphorus to give α – halo carboxylic acids.

→ Methyl ketones can be distinguished from other ketones by iodoform test.

→ Aromatic carboxylic acids undergo electrophilic substitution reactions in which the carboxyl group acts as a deactivating and meta-directing group.

Students can go through TS Inter 2nd Year Chemistry Notes 11th Lesson Haloalkanes and Haloarenes will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 11th Lesson Haloalkanes and Haloarenes

→ Alkyl/aryl halides may be classified as mono, di or polyhalogen (tri-tetra, etc) compounds depending upon whether they contain one, two or more halogen atoms in their structures.

→ Halogen compounds containing sp³ C – X bond (X = F, Cl, Br, I) include Alkyl halides (haloalkanes), Allylic halides and Benzylic halides.

→ Alkyl halides are further classified as pri-mary (1°). secondary (2°) or tertiary (3°) according to the nature of the carbon to which the halogen is attached.

→ Halogen compounds containing sp² C – X bond include Vinylic halides and Aryl halides.

→ Dihaloalkanes are called geminal (gem) halides if halogen atoms are present in the same carbon atom and vicinal (vie) halides if halogen atoms are present on adjacent carbon atoms.

→ Since halogen atoms are more electronegative than carbon, the carbon-halogen bond of alkyl halide is polarised.

→ C – X bond length increases from C – F to C – I.

→ Alkyl halides are prepared from alcohols on reaction with concentrated halogen acids (HX), PCl₃, PCl₅ Or SOCl₂.

→ Free radical chlorination or bromination of alkanes gives a complex mixture of isomeric mono and polyhaloalkanes.

→ Aryl chlorides or bromides can be prepared by reaction of the hydrocarbon with chlorine or bromine at room temperature in the presence of halogen carrier like Fe, AlCl₃ or SbCl₅.

→ When an aromatic primary amine reacts with nitrous acid (NaNO₂ + HX) at 0 – 5°C, a diazonium salt is formed. The diazonium salt solution reacts with cuprous chloride or cuprous bromide-, the diazonium group is replaced by – Cl or – Br. This reaction is known as Sandmeyer s reaction.

→ When diazonium salt solution is shaken with KI solution the diazonium group is replaced by iodine.

→ Addition of bromine in CCl₄ to an alkene results in discharge of reddish brown colour of bromine. This is an important test for the detection of unsaturation in a molecule.

→ Alkyl fluoride is prepared by heating an alkyl chloride or bromide in the presence of a metallic fluoride such as AgF₂, Hg₂F₂ etc (swarts reaction).
CH₃Br + AgF → CH₃F + AgBr

→ Haloalkanes are only very slightly soluble in water.

→ The chemical reactions of haloalkanes may be divided into three categories.

• Nucleophilic substitution
• Elimination reactions
• Reaction with metals.

→ The order of reactivity of alkyl halides towards S_N¹ and S_N² reactions is as follows :

• For S_N² reaction : CH₃X > primary halide > secondary halide > tertiary halide.
• For S_N¹ reaction: tertiary halide > secondary halide > primary halide > CH₃X.

→ A carbon atom joined to four different atoms or groups is called an asymmetric carbon or stereocentre or chirality centre.

→ The objects which are non-superimposable on their mirror images are said to be chiral and this property is known as chirality. Objects which are superimposable on their mirror images are called achiral.

→ Optical activity is the ability of a chiral sub-stance to rotate the plane of plane-polarised light.

→ The three dimensional arrangement of atoms or groups at a chirality centre is called the absolute configuration.

→ The stereoisomers related to each other as non-superimposable mirror images are called enantiomers.

→ S_N² reactions of optically active alkyl halides are accompanied by inversion of configuration.

→ S_N¹ reactions of optically active alkyl halides are accompanied by racemisation.

→ Zaitsev rule (Saytzef rule) : “In dehydro- halogenation reactions, the preferred product is that alkene which has greater number of alkyl groups attached to the doubly bonded carbon atoms”.

→ Alkyl magnesium halides (RMgX) are known as Grignard reagents.

→ A number of polyhalogen compounds e.g., dichloromethane, chloroform, iodoform, CCl₄, freon and DDT have many industrial applications.

→ Chloroform is slowly oxidised by air in the presence of light to a very poisonous gas, carbonyl chloride, also known as phosgene, COCl₂. Hence chloroform is stored in closed amber coloured bottles completely filled so that air is kept out.

→ Dichlorodifluoro methane (CCl₂F₂) is known as Freon 12.

→ Paul Muller discovered the effectiveness of DDT as an insecticide.

Students can go through TS Inter 2nd Year Chemistry Notes 10th Lesson Chemistry in Everyday Life will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 10th Lesson Chemistry in Everyday Life

→ Drugs are chemicals of low molecular masses ( ~ 100 to 500 u) which interact with macro- molecular targets and produce a biological response.

→ Drugs are called medicines when their biological response is therapeutic and useful.

→ Use of chemical for therapeutic effect is called chemotherapy.

→ Drugs are classified on the basis of

• Pharmacological effect
• drug action
• chemical structure and
• molecular targets.

→ Proteins which perform the role of biological catalysts in the body are called enzymes.

→ Proteins that are crucial to body’s communication process are called receptors.

→ Drugs can block the binding site of the enzyme and prevent binding of substrate or can inhibit the catalytic activity of the enzyme. Such drugs are called enzyme inhibitors.

→ In the body message between two neurons and that between neurons to muscles is communicated through certain chemicals known as chemical messengers.

→ Drugs that bind to the receptor site and inhibit its natural function are called antagonists.

→ Drugs that mimic the natural messenger by switching on the receptor are called agonists.

→ Antacids are used to counteract the effects of excess acid in the stomach.

→ A chemical, histamine, stimulates the secretion of pepsin and hydrochloric acid in the stomach.

→ Cimetidine (Tegamet) and ranitidine (Zantac) are used as antacids.

→ Histamine is a potent vasodilator. It is responsible for the nasal congestion associated with common cold and allergic response to pollen.

→ Bromphenaramine (Dimetapp) and terfenadine (Seldane) act as antihistamines.

→ Tranquilizers and analgesics are neurologically active drugs.

→ Tranquilizers are a class of chemical com-pounds used for the treatment of stress and mild or even severe mental diseases.

→ Iproniazid and phenelzine are antidepressant drugs.

→ Chlordiazepoxide and meprobamate are relatively mild tranquilizers suitable for relieving tension.

→ Equanii is used in controlling depression and hypertension.

→ Barbiturates are hipnotic, i.e., sleep produc-ing agents.

→ Analgesics reduce or abolish pain without causing disturbances of nervous system.

→ Aspirin and paracetamol are non – narcotic analgesics.

→ Drugs which reduce fever are called anti-pyretics.

→ Morphine narcotics are chiefly used for the relief of post operative pain, cardiac pain etc.

→ An antimicrobial drug tends to destroy / prevent development or inhibit pathogenic action of microbes such as bacteria, fungi, virus and other parasites selectively.

→ Salvarsan was discovered by Paul Ehrlich. It was used for the treatment of syphilis.

→ Penicillin was discovered by Alexander Fleming.

→ Ampicillin, Amoxycillin, Chloramphenicol are examples for broad spectrum antibiotics.

→ Penicillin G has a narrow spectrum.

→ Antiseptics and disinfectants are chemicals which either kill or prevent the growth of micro organisms.

→ Antiseptics are applied to living tissues such as wounds, cuts, ulcers and diseased skin surfaces.

→ Dettol is a mixture of chloroxylenol and terpineol.

→ Boric acid in dilute aqueous solution is a weak antiseptic for eyes.

→ Disinfectants are applied to inanimate objects such as floors, drainage system, instruments etc.

→ Antifertility drugs are used to check population explosion.

→ Birth control pills essentially contain a mixture of synthetic estrogen and progesterone derivatives.

→ Norethindrone is an example of synthetic progesterone derivative most widely used as antifertility drug.

→ The estrogen derivative which is used in combination with progesterone derivative is ethynylestradiol (novestrol).

→ Artificial sweeteners are preferred by diabetic persons and people who need to control intake of calories.

→ Saccharin, Aspartame, Sucralose, Alitame, etc. are examples for artificial sweeteners.

→ Food preservatives prevent spoilage of food due to microbial growth.

→ Sodium benzoate is an important food preservative.

→ Salts of sorbic acid and propanoic acid are also used as food preservatives.

→ Anti oxidants help in food preservation by retarding the action of oxygen on food.

→ Butylated hydroxy toluene (BHT) and Butylated hydroxy anisole (BHA) are the most familiar antioxidants. Sometimes these are used along with citric acid for more effective action.

→ Soaps and detergents are used as cleansing agents.

→ Soaps used for cleaning purpose are sodium or potassium salts of long chain fatty acids, e.g., stearic, oleic and palmitic acids.

→ Sodium or potassium soaps do not work in hard water. Synthetic detergents can be used both in soft and hard water.

→ Branched chain detergents are not easily degraded by bacteria easily. Slow degradation of detergents leads to their accumulation and cause environmental pollution.

→ Unbranched hydrocarbon detergents are biodegradable.

Students can go through TS Inter 2nd Year Chemistry Notes 9th Lesson Biomolecules will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 9th Lesson Biomolecules

→ Carbohydrates are optically active polyhydroxy aldehydes or ketones or molecules which provide such units on hydrolysis.

→ Most of the carbohydrates have the general formula C_x(H₂O)_y.

→ Carbohydrates which are sweet to taste are called sugars.

→ Carbohydrates are also called saccharides.

→ On the basis of hydrolysis, carbohydrates are classified into monosaccharides, oligosaccharides and polysaccharides.

→ Carbohydrates which cannot be hydrolysed into simpler units are called monosaccharides. Ex: Glucose, fructose.

→ Carbohydrates which yield two to ten mono-saccharide units on hydrolysis are called oligosaccharides.

→ Sucrose (Cane sugar) is a disaccharide. It gives one molecule of glucose and one molecule of fructose on hydrolysis.

→ Maltose on hydrolysis gives two molecules of glucose only.

→ Carbohydrates which yield a large number of monosaccharide units on hydrolysis are called polysaccharides. Ex: Starch, cellulose.

→ Glucose is an aldohexose whereas fructose is a ketohexose. Glucose is also known as dextrose.

→ In the laboratory glucose is prepared by boiling sucrose with dil. HCl or H₂SO₄ in alcoholic solution.

→ Starch on boiling with dilute H₂SO₄ at 120°C and under pressure, undergoes hydrolysis and gives Glucose.

→ On prolonged heating with HI glucose forms n – Hexane.

→ Glucose reacts with hydroxylamine to give an oxime.

→ Glucose is oxidised by bromine water to give gluconic acid.

→ Acetylation of glucose with acetic anhydride gives glucose pentaacetate.

→ Glucose and gluconic acid on oxidation with nitric acid give saccharic acid.

→ The letter ‘D’ or ‘L’ before the name of any compound indicates relative configuration of a particular stereo isomer.

→ Glucose is correctly named as D – (+) – glucose. Here (+) represents dextrorotatory nature.

→ The open chain structure of glucose explained most of its properties but it could not explain some facts regarding glucose. Glucose does not give Schiff’s test and it does not form bisulphite addition product with NaHSO₃.

→ A pyranose ring structure was proposed for glucose.

→ Glucose exists in two cyclic hemiacetal forms which differ in their configuration at C₁, called the anomeric carbon. These isomers
i. e., α – form and β – form are called anomers.

→ Glucose is dextrorotatory whereas fructose is laevorotatory.

→ Fructose is given a furanose ring structure.

→ The two monosaccharide units in a disaccharide are joined by an oxide linkage formed by the loss of a water molecule. Such a linkage between two monosaccharide units through oxygen atom is called glycosidic linkage.

→ Sucrose on hydrolysis gives equimolar mixture of glucose and fructose. The product is called invert sugar.

→ Lactose on hydrolysis gives galactose and glucose.

→ Starch is a polymer of a – glucose and consists of two components – Amylose and Amylopectin.

→ The carbohydrates are stored in animal body as glycogen.

→ Proteins are the polymers of about 20 different α – amino acids which are linked by peptide bonds.

→ Amino acids which can be synthesised in the body are called non – essential amino acids. Ex: Glycine, Alanine.

→ Amino acids which cannot be synthesised in the body and must be obtained through diet are known as essential amino acids. Ex: Valine, Lysine.

→ When a protein in its native form, is subjected to physical change like change of temperature or chemical change like change in pH, it loses its biological activity. This is called denaturation of protein.

→ Enzymes are biocatalysts which speed up the reactions in biosystems.

→ Vitamins are organic molecules which are required in small quantities in our diet and their deficiency causes specific diseases.

→ Nucleic acids are five membered ring sugars linked by phosphate groups.

→ Nucleic acids are mainly of two types.

• Deoxyribonucleic acid (DNA) and
• Ribo-nucleic acid (RNA). Nucleic acids are also called polynucleotides.

→ Hormones are molecules that act as intercellular messengers.

→ Hormones have several functions in the body and help to maintain the balance of biological activities in the body.

Students can go through TS Inter 2nd Year Chemistry Notes 8th Lesson Polymers will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 8th Lesson Polymers

→ Polymers are the backbone of four major industries namely, plastics, elastomers, fibres, paints & varnishes.

→ Polymer is defined as very large molecule having high molecular mass.

→ Polymers are also called macromolecules.

→ The repeating structural unit of a macro-molecule is called a monomer.

→ The process of formation of polymers from respective monomers is called polymerisation.

→ Based on source polymers are classified into natural polymers, semisynthetic polymers and synthetic polymers.

→ Based on structure, polymers are classified into linear polymers, branched chain polymers and cross linked or network polymers.

→ Cellulose, starch, rubber are examples for natural polymers.

→ Cellulose acetate (rayon) and cellulose nitrate are examples for semisynthetic polymers.

→ Buna – S, polythene, nylon 6,6 are examples for synthetic polymers.

→ HDP, PVC etc., are examples for linear polymers.

→ LDP is an example for branched chain polymers.

→ Bakelite, melamine etc., are examples for cross linked polymers.

→ On the basis of mode of polymerisation polymers are classified into addition polymers and condensation polymers.

→ An addition polymer is formed by the repeated addition of monomer molecules containing double bonds.

→ Polymers formed by the polymerisation of a single monomeric species are called homo-polymers. Ex.: Polythene.

→ Polymers formed by the polymerisation of two different monomeric species are called copolymers. Ex.: Buna – S, Buna – N.

→ Polymers formed by the repeated condensation reaction between two different monomeric species having two or three functional groups are called condensation polymers. Ex.: Nylon 6,6. ’

→ On the basis of inter molecular forces, polymers are classified into

• Elastomers,
• Fibres,
• Thermoplastic polymers and
• Thermosetting polymers.

→ Elastomers are rubber-like solids with elastic properties. Ex.: Buna – S, Buna – N etc.

→ Fibres are thread forming solids with high tensile strength and high modulus.
Ex.: Terylene, Nylon 6,6.

→ Thermoplastic polymers are those which soften on heating and become rigid again on cooling. Ex.: Polythene, polystyrene.

→ Thermosetting polymers are those which become hard on heating. They cannot be softened on heating. Ex. : Bakelite, urea- formaldehyde resins.

→ Addition polymerisation takes place through the formation of either free radicals or ionic species.

→ Alkyl aluminium and titanium chloride is called Ziegler-Natta catalyst.

→ The earliest Ziegler – Natta catalysts were combinations of titanium chloride, TiCl₄ and diethyl aluminium chloride [(C₂H₅)₂ Al Cl].

→ There are two types of polythene.

• Low density polythene (LDP) and
• High density polythene (HDP).

→ Polytetra fluoroethene (Teflon) is chemically inert and resists attack by corrosive reagents. It is used in making oil seals, gaskets etc.

→ Polyacrylonitrile is a substitute for wool in making commercial fibres, such as orlon.

→ Condensation polymerisation is also called step growth polymerisation.

→ Terylene or dacron is formed by the interac-tion of ethylene glycol and terephthalic acid.

→ Nylon 6,6 is obtained by the condensation polymerisation of hexamethylene diamine with adipic acid under high pressure and at high temperature. It is used in making sheets, bristles for brushes, textiles etc.

→ Nylon 6 or perlan – L is obtained by heating caprolactam with water at high temperature. It is used in the manufacture of tyre cords, fabrics and ropes.

→ Phenol – formaldehyde polymers are obtained by the condensation reaction of phenol with formaldehyde in the presence of either an acid or a base catalyst. The initial product is a linear product – Novolac used in paints.

→ Novolac on heating with formaldehyde undergoes cross linking to form an infusible solid mass called bakelite.

→ Bakelite is used in making combs, electrical switches etc.

→ Melamine formaldehyde polymer is formed by the condensation polymerisation of melamine and formaldehyde. It is used in making unbreakable crockery.

→ Buna – S is a copolymer formed by the polymerisation reaction of 1, 3 – butadiene and styrene.

→ Buna – S is used in the manufacture of autotyres, footwear components, cable insulation etc.

→ Natural rubber is a linear polymer of isoprene.It is also called Cis-1,4-polyisoprene.

→ The process of heating a mixture of raw rubber with sulphur and an appropriate additive at a temperature range between 373 K to 415 K is called vulcanisation. On vulcanisation sulphur forms cross links at the reactive sites of double bonds and thus rubber becomes hard.

→ Neoprene is a synthetic rubber obtained by the free radical polymerisation of chloroprene.

→ Buna – N is obtained by the co-polymerisation of 1, 3 – butadiene and acrylonitrile in the presence of a peroxide catalyst. It is used in making oil seals, tank lining etc.

→ The average molecular masses of polymers are expressed as

• Number average molecular mass (M̅_n) and
• Weight average molecular mass (M̅_w)

→ Both M̅n and M̅w have no units.

→ The ratio between weight average molecular mass (M̅_w) and number average molecular mass (M̅_n) of a polymer is called Poly Dispersity Index (PDI).

→ Poly β – hydroxybutyrate – co-β-hydroxy valerate (PHBV) and Nylon 2 – nylon 6 are examples for biodegradable polymers.

→ PHBV is obtained by the copolymerisation of 3 – hydroxybutanoic acid and 3 – hydroxy- pentanoic acid. PHBV is used in speciality packaging, orthopaedic devices and in con¬trolled release of drugs.

→ Nylon 2 – nylon 6 is an alternating polyamide copolymer of glycine and amino ceproic acid.

→ Polypropene is used in the manufacture of ropes, toys, pipes etc.

→ Polyvinyl chloride (PVQ is used in the manufacture of rain coats, hand bags, water pipes etc.

→ Urea-formaldehyde resin is used in making unbreakable cups and laminated sheets.

→ Glyptal obtained by the polymerisation of ethylene glycol and phthalic acid is used in the manufacture of paints and lacquers.

→ Bakelite obtained by the polymerisation of phenol and formaldehyde is used in making combs, electrical switches, computer discs etc.

Students can go through TS Inter 2nd Year Chemistry Notes 7th Lesson d and f Block Elements & Coordination Compounds will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 7th Lesson d and f Block Elements & Coordination Compounds

→ Elements with partially filled d-orbitals in the penultimate shell in their atoms or in the ions in principal oxidation state are called transition elements.

• 3d series contain Sc (21) to Zn (30).
• 4d series contain Y(39) to Cd (48).
• 5d series contain La (57) to Hg (80).
• The fourth row of 6d is still incomplete.

→ General electronic configuration of d-block elements is (n – 1) d^1-10 ns^1-2.

→ Transition elements exhibit different oxidation states, formation of aqueous coloured ions, and ability to form complex compounds with a variety of ligands.

→ Transition metals have high melting points. The high melting points are attributed to the involvementtsf greater number of electrons in the interatomic metallic bonding.

→ As shielding effect of d electrons is poor, net electrostatic attraction between the nuclear charge and the outermost electron increases and the ionic radius decreases.

→ There is a gradual size decrease from La (57) to Lu (71) which is known as lanthanoid contraction.

→ Transition elements show variable oxidation states due to involvement of ns² electrons and some or all electrons in (n – 1) d ele¬ctrons as the energy difference between ns and (n – 1) d sublevels is less.

→ Paramagnetism arises from the presence of unpaired electrons. The magnetic moment is determined by spin only formula.
μ = \(\sqrt{n(n+2)}\)
where n is the no. of unpaired electrons and μ is the magnetic moment in Bohr magneton.

→ The colour exhibited by transition metal ions is due to d-d transitions.

→ Transition metal ions form complex compounds. This is due to the comparatively smaller sizes of the metal ions, their high ionic charges and the availability of d-orbi- tals for bond formation.

→ Zn++ is colourless due to non-availability of unpaired d-electrons.

→ Tetrahedral complexes do not show geometrical isomerism because the relative positions of unidentate ligands attached to central metal atom are the same with respect to each other.

→ When (n – 1) d orbitals participate in hybridisation, inner orbital complex form. They are called low spin complexes. When d- orbitals of outer shell participate, outer orbital complexes form. They are high spin complexes.

→ Valence bond explains the formation of complexes. Central metal ion makes available vacant d-orbitals. Ligands donate electrons to form coordinate covalent bonds.
(n – 1) d, ns, np or ns, np, nd orbitals hybridise to form of set of equivalent orbitals of definite geometry such as octahedral, square planar and so on. These hybridised orbitals overlap with ligand orbitals that can donate electron pairs for bonding.

→ In the presence of ligands, d-orbitals are split into two groups.

→ Ligands which cause large splitting are called strong field ligands.

→ Ligands which cause low value for splitting are called weak field ligands.

→ The metal-carbon bond in metal carbonyls possess both σ and π character. The M – C σ bond is formed by the donation of the pair of electrons on the carbonyl carbon into a vacant orbital of the metal. The M – C π bond is formed by the donation of a pair of electrons from a filled d-orbital of metal into the vacant antibonding π* orbital of carbon monoxide.

→ The instability constant is the reciprocal of formation constant

→ Hardness of water is estimated using simple titration with Na₂EDTA. The Ca²⁺ and Mg²⁺ ions form stable complexes with EDTA.

→ Coordination compounds are used as catalysts for many industrial processes.
Ex : Rhodium complex [(Ph₃P)₃ RhCl], is used for hydrogenation of alkenes:

Students can go through TS Inter 2nd Year Chemistry Notes 6th Lesson P-Block Elements will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 6th Lesson P-Block Elements

→ Group 15 elements include Nitrogen, Phos-phorus, Arsenic, Antimony and Bismuth.

→ Nitrogen and Phosphorous are non-metals, arsenic and antimony are metalloids. Bismuth is a typical metal.

→ Nitrogen is inert due to high bond dissociation enthalpy of N = N.

→ Stability and basicity of hydrides decreases from NH₃ to BiH₃.
NH₃ > PH₃ > ASH₃ > SbH₃ > BiH₃

→ Pentoxides are more acidic than trioxides N₂O₅ > N₂O₃.

→ Pentahalides are more covalent than trihalides because the element in the higher oxidation state exerts more polarising power.

→ Ammonia is prepared by Haber s process. N₂, and H₂, combine to give ammonia. Low tem¬perature and high pressure are required for high yield.

→ White phosphorus consists of tetrahedral P₄ molecules held by van der Waal’s forces.

→ Holme’s signal uses calcium carbide and calcium phosphide.

→ Oxoacids of phosphorus are

• • Orthophosphoric acid H₃PO₄
  • Pyrophosphoric acid H₄P₂O₇
  • Orthophosphorus acid H₃PO₃
  • Hypophosphorus acid H₃PO₂

→ Oxygen, Sulphur, Selenium, Tellurium, and Polonium constitute Group 16 of the periodic table. They are known as chalcogens as they are ore forming.

→ Oxygen cannot show higher oxidation state due to non-availability of d-orbitals in outermost shell.

→ Stability of hydrides decreases H₂O > H₂S > H₂Se > H₂Te > H₂Po.

→ The acidic nature of hydrides of Group 16 increases. H₂O < H₂S < H₂Se < H₂Te < H₂Po.

→ Molecular oxygen is paramagnetic. It contains two unpaired electrons in antibonding π* orbitals.

→ Ozone is prepared by passing silent electric discharge through pure and dry oxygen.

→ Stable form of sulphur at room temperature is rhombic sulphur.

→ Monoclinic sulphur is stable above 369K. At 369K both Rhombic and Monoclinic sulphur are stable. This temperature is called transition temperature.

→ H₂SO₄ is prepared by contact process.

→ H₂SO₄ is needed for manufacture of hundreds of compounds and also in manufacture of fertilisers.

→ Fluorine, Chlorine, Bromine, Iodine and Astatine are members of Group 17. They are known as halogens.

→ All these elements have ns2np5 electronic configuration. .

→ All the halogens are highly reactive. They behave as oxidising agents.

→ Stability of Hydrogen halides decreases down the group due to decrease in bond dissociation enthalpy.
HF > H – Cl > H-Br > H – I

→ The acidic strength of hydrogen halides varies in the order HF < HCl < HBr < HI. → HF has highest boiling point and it is the only liquid. Others are gases. Order of B.Ps. HF > HI > HBr > HCl
The high boiling point of HF is due to hydrogen bonds among HF molecules.

→ In OF₂ and O₂F₂ oxygen has + 2 and +1 oxida¬tion states. They are termed oxygen fluorides. O₂F₂ oxidises plutonium to P₄F₆. It is used in removing plutonium as P4F6 from spent nuclear fuel.

→ Chlorine forms Cl₂O, ClO₂, Cl₂O₆ and Cl₂O₇.
ClO₂ is used as a bleaching agent for paper Pulp.

→ I₂O₅ is a very good oxidising agent and is used In the estimation of carbon monoxide.
I₂O₅ + 2CO → Ir₅CO₂

→ Halogens combine amongst themselves to form a number of compounds known as Interhalogens. They are classified as :
AX, AX₃, AX₅, AX₇ where A is bigger halogen.

→ Interhalogens are more reactive than halogens. A – X bond is weaker than X – X bond.

→ ClF₃ is T-shaped. BrF₅ is square pyramidal and IF. has pentagonal bipyramidal.

→ Among the different oxoacids of chlorine, the acidic character follows the order HOCl < HClO₂, < HClO₃, < HClO₄.

→ The acidic character of hypohalous acids varies as HClO > HBrO > HIO.

• ICl + H₂O → HCl + HOI
• ICl₃ + 2H₂O → 3HCl + HIO₂
• BrF₅ + 3H₂O → 5HF + HBrO₃

→ Group 18 consists of six elements. They are Helium, Neon, Argon, Krypton, Xenon and Radon.

→ All noble gases occur in atmosphere except radon.

→ Their atmospheric abundance in dry air is – 1 % by volume of which argon is the major constituent.

→ The commercial source of Helium is natural gas.

→ Xenon and Radon are the rarest elements of the group.

→ Radon is obtained as a decay product of
²²⁶₈₈Ra → ²²⁶₈₆Rn+ ⁴₂He

→ All noble gases have general electronic con-figuration ns np6 except Helium which has 1s².

→ They have large positive values of electron gain enthalpy.

→ Helium has the lowest boiling point (4.2K).

→ Among a few compounds of Krypton (KrF₂) has been studied in detail.

→ Xenon forms three binary fluorides XeF₂, XeF₄ and XeF₆ by the direct reaction under appropriate experimental conditions.

→ Helium is non-inflammable and light gas. It is used in filling balloons for meteorological observations. It is also used in gas cooled nuclear reactors.

→ Neon is used in discharge tubes and fluoroscent bulbs.

→ Argon is used mainly t0 provide an inert atmosphere in high temperature metallurgical processes and for filling electric bulbs. It is also used in labs for handling air sensitive substances.

→ There are no significant uses of Xenon and Krypton. They are used in light bulbs designed for special purposes.

Students can go through TS Inter 2nd Year Chemistry Notes 5th Lesson General Principles of Metallurgy will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 5th Lesson General Principles of Metallurgy

→ The naturally occurring chemical substances in the earth’s crust which are obtained by mining are known as minerals.

→ Very few minerals are chemically and com-mercially viable to be used as sources of extraction are known as ores.

→ Ores are usually associated with earthy materials called gangue.

→ The process of extraction and isolation of the metal from its naturally occurring com-pounds is called metallurgy.

→ Extraction involves the following major steps.

• Concentration of the ore.
• Isolation of the metal from the concentrated ore by chemical or electrochemical methods.
• Purification of the metal.

→ Removal of the gangue from the ore is known as concentration, dressing or benefaction.

→ Sulphide ores are concentrated by froth floatation process.

→ If either the ore or the gangue is a magnetic substance, magnetic separation method is used.

→ Isolation of metals from concentrated ore involves calcination or roasting and reduction.

→ Reduction of the metal oxide involves heating it with reducing agents.
C or CO or A/ or any other active metal.

→ Ellingham diagram consists of plots of Δ_fG° Vs T for formation of oxides of elements.

→ Such diagrams help us in predicting the feasibility of thermal reduction of ore.

→ The criterion of feasibility is that at a given temperature, Gibbs energy of the reaction must be negative.

→ Iron obtained from Blast furnace contains 4% carbon and many impurities in smaller amounts (eg : P, S, Si, Mn). This is known as pig iron.

→ Copper is extracted from CuFeS₂ FeS is oxidised to FeO and is removed as FeSiO₃.

→ Bauxite is leached with NaOH which removes impurities.

→ A metal extracted by any method is usually contaminated with some impurity. For obtaining metals of high purity, the follow¬ing methods are in vogue.

→ Distillation : Useful for low boiling metals like zinc and mercury containing high boiling metals as impurities.

The extracted metal in the molten state is distilled to obtain the pure metal as distillate.

→ Liquation: Low melting metal like tin can be made to flow on a sloping surface leaving behind high melting inpurities.

→ Zone refining: Impurities are more soluble in the melt than in the solid state of the metal. As the heater moves forward the pure metal crystallises out of the melt and the impurities pass on to the adjacent molten zone. Impurities get concentrated at one end. This end is cut off.

→ Aluminium foils are used as wrappers for Chacolates.

→ Copper alloys are tougher than the metal itself. Ex : Brass (with zinc, and bronze (with tin).

→ Zinc is used for galvanising iron.

→ Cast iron is used for casting stoves, railway sleepers etc.

Students can go through TS Inter 2nd Year Chemistry Notes 4th Lesson Surface Chemistry will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 4th Lesson Surface Chemistry

→ The phenomenon of attraction and conse-quent accumulation or adherence of mole-cules of a substance on the surface of a liquid or solid is called adsorption.

→ The phenomenon of concentration of mole-cules of a gas or a liquid on a surface of solid or liquid is called absorption.

→ The substance adsorbed on the surface of a liquid or solid is called adsorbate.

→ The substance on whose surface the adsorption occurs is called adsorbent. Eg. in the adsorption of acetic acid on charcoal adsor-bate is acetic acid and charcoal is adsorbent.

→ Adsorption is two types Physical adsorption and Chemical adsorption.

→ The adsorption due to physical forces or – van der Waals’ forces is known as physical adsorption. This is also known as van der Waals’ adsorption.

→ If the adsorption is due to chemical attractive forces, it is known as chemical adsorption.

→ The amount of a gas adsorbed on metal surface or a solid depends on

• surface area of the adsorbent
• nature of gas
• pressure of gas
• temperature.

→ The graph showing relation to pressure (p) and the ratio of masses of adsorbate (x) and adsorbent (m) at a constant temperature is called adsorption isotherm.

→ Freundlich adsorption isotherm is \(\frac{x}{m}\) = Kp^1/n which indicates that at any given temperature the amount of gas (x) adsorbed by unit mass of the adsorbent (m) is related to this adsorption equilibrium pressure (p).

→ The graph showing the relation between x/m and temperature at constant pressure is called as adsorption isobar.

→ The substances which accelerates the rate of a reaction is known as positive catalyst. Positive catalyst increase the rate of reac-tion by lowering the activation energy.

→ Substances which decreases the rate of a reaction or retard the reaction are called negative catalyst or inhibitors.

→ Substance which itself has no catalytic acti-vity but will increase the activity of catalyst is called promoter or activator. A promotor thus be regarded as a catalyst for catalyst e.g. Al₂O₃ K₂O, MO powder act as promoter to iron catalyst in Haber process for the manufacture of ammonia.

→ The substances which reduces or even com-pletely destroy the activity of a catalyst are known as catalytic poisons or anticatalysts.

→ If one of the products or intermediate formed in a reaction acts as catalyst for the same reaction it is known as autocatalyst and the phenomenon is known as autocatalysis.

→ If the catalyst and reactants are not in the same phase, then it is known as heterogen-eous catalysis. Generally the catalyst is solid while the reactants are liquids or gases. Most of the solid catalysts are either transition metals or their compounds.

→ Zeolites can act as molecular seives which allow certain molecules which are smaller than the pore size to pass through them while the molecules bigger than the pore size cannot pass through them.

→ Enzymes are protein molecules which are complex nitogeneous organic compounds which are present in the living plants and animals.

→ Metal ions such as Na+, Mn²⁺, Co²⁺, Cu²⁺ etc which activate the enzyme catalysis are called activators.

→ If the particle size of the solute in the binary system is in the range of 1 μ to 1 mμ a colloidal solution is formed.

→ In the colloids the phase constituting the colloidal particles is called dispersion phase while the medium in which the colloidal particles are distributed is called dispersion medium. The dispersion medium or disper¬sion phase may be solid or liquid.

→ The dispersion medium in a colloid is named as lyo. Colloidal solutions in which the parti¬cles of the dispersed phase have great affinity for the dispersion medium are called lyophilic colloids. The colloidal solutions in which particles of the dispersed phase have no affinity for the dispersion medium are called lyophobic colloids.

→ If water is dispersion medium lyophilic colloids are called hydrophilic colloids while lyophobic colloids are called hydrophobic colloids.

→ The process of transferring back a preci-pitate into colloidal form is called peptisation. It is the reverse of coagulation.

→ When a beam of light is made to fall on a colloidal solution, the path of the beam of light is illuminated by a bluish light. The luminosity by the path of beam is known Tyndall effect. It is due to the scattering of light from the surface of the colloidal par¬ticles. The scattering of light due to the absorption of light energy and then scatter the light of shorter wavelength.

→ The constant rapid zig-zag of colloidal particles in a collodial solution is known as Brownian movement named after its discoverer.

→ The migration of electrically charged sol particles under an applied electric field is called electrophoresis strictly cataphoresis or anaphoresis according to the electrode to which the particles move.

→ The potential difference between the fixed layer and the diffused layer having oppo-site charge is called the electro kinetic potenital or zeta potential and the double layer is called electrical double layer.

→ At a particular pH the sol particles become neutral and exhibit no movement in an ele-ctric field and this pH is called isoelectric point.

→ When electrophoresis of dispersed particles is prevented by suitable means the medium can be made to move under the influence of an applied potential. This phenomenon is referred to as electro osmosis.

→ Coagulation or flocculation is the process of breaking up of a colloidal solution by which colloidal particle come close and result in the precipitation of the dispersed phase.

→ If a colloidal solution is stored for longer periods smaller particles dissolved and crystallise out on the larger particles causing the coagulation of colloid. This is known as ageing.

→ The minimum concentration of an electrolyte which is able to cause coagulation or flocculation of sol is termed as flocculation value.

→ The coagulation of lyophilic colloid by adding salt solutions of high concentrations is called ‘salting out’. This may be due to the removal of solvent layer around the lyophilic colloid by the salt.

→ The process by which the sol particles are prevented from coagulation by electrolyte due to the previous addition of some lyophilic sol is called protectioii of colloid.

→ The number of milligrams of protective colloid which just prevents the coagulation of 10 ml of given gold sol when 1 mL of 10% solution of NaCl is added to it is called gold number.

→ A colloidal system involving one liquid dispersed in another is known as emulsion.

→ The substances that stabilises an emulsion are called emulsifier or emulsifying agent.

→ Emulsions are two types

• oil in water (0/w)
• water in oil (w/o) depending on the dispersion medium and dispersion phase.

Students can go through TS Inter 2nd Year Chemistry Notes 3rd Lesson Electrochemistry and Chemical Kinetics will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 3rd Lesson Electrochemistry and Chemical Kinetics

→ In an electrolytic cell electrical energy is converted into chemical energy while in Galvanic cell or Voltaic cell chemical energy is converted into electrical energy.

→ In both galvanic and electrolytic cells oxidation take place at anode and reduction take place at cathode.

→ Nernst equation gives the dependence of the electrode. Potential on the concentration of ions with which the electrode is reversible.

→ For a metal electrode the reduction reaction is Mnⁿ⁺ + ne^– ⇌ M. The Nernst equation to calculate the electrode potential at different concentration is
E = E° – \(\frac{2.303 \mathrm{RT}}{\mathrm{nF}}\) log \(\frac{[\mathrm{M}]}{\left[\mathrm{M}^{\mathrm{n}+}\right]}\)
E = E° – \(\frac{2.303 \mathrm{RT}}{\mathrm{nF}}\)log C
Since M is solid, its activity will be unity.

→ For a non – metal electrode the reduction reaction is A + ne^– ⇌ A^n-. The Nernst equation to calculate electrode potential at different concentration is
E = E° – \(\frac{2.303 \mathrm{RT}}{\mathrm{nF}}\) log\(\frac{\left[\mathrm{A}^{\mathrm{n}-}\right]}{\left[\mathrm{A}^{-}\right]}\) or
E = E – \(\frac{2.303 \mathrm{RT}}{\mathrm{nF}}\) log [A^n-]

→ General equation for electrode potential of any electrode is
E = E° – \(\frac{2.303 \mathrm{RT}}{\mathrm{nF}}\) log\(\frac{\text { [Products }]}{[\text { Reactan } t s]}\)

→ For a cell reaction of the type aA + bB ⇌ cC + dD
The Nernst equation
E = E° – \(\frac{0.0591}{n}\) log \(\frac{[\mathrm{C}]^{\mathrm{c}}[\mathrm{D}]^{\mathrm{d}}}{[\mathrm{A}]^{\mathrm{a}}[\mathrm{B}]^{\mathrm{b}}}\)

→ From the standard Gibbs energy the equilibrium constant by the equation
ΔG° = – RT /n K.

→ Substances whose melts or aqueous solutions conduct electric current are called electrolytes. All salts, acids and based are referred to as electrolytes.

→ Substances whose melts or aqueous solutions do not conduct are called non – electrolytes e.g. non – polar covalent substances like urea, glucose, sugar etc., are non – electrolyte.

→ The flow of electrons across the boundary is accompanied by chemical reaction i.e., oxidation-reduction. Such a reaction is called electrolysis. Electrolysis take place only at electrodes.

→ If a substance ionise completely, it is known as strong electrolyte while the substances which show very little ionisation in solution are called weak electrolytes.

→ Kohlrausch’s law states that the equivalent conductivity of an electrolyte at infinite dilution (λ₀) is the sum of the equivalent conductivities of the cation and anions.
λ₀ = λ₀⁺ + λ₀^–
where λ₀⁺ is the ionic conductance of
the cation and λ₀^– is the ionic conductance of the anion.

→ Kohlrauch law is also useful to calculate As for any electrolyte from the X° of individual ions.

→ Equivalent conductance of weak electrolytes can be calculated from the conductances of completely dissociated strong electrolytes
e.g. Λ°_CH3COOH = Λ°_CH3COONa + Λ°_HCl – Λ°_NaCl

→ First law : The amount of the substance liberated or deposited or dissolved at an electrode during electrolysis of an electro¬lyte is directly proportional to the quantity of electricity passing through the solution of electrolyte or the melt.

→ Electrochemical equivalent of a substance is the amount of substance deposited or liberated or dissolved or underwent electrode reaction at an electrode by passing one ampere current for one second i.e., one coulomb.

→ One Faraday i.e., 96,500 coloumbs is equal to the charge present on one mole
(6.023 × 10²³) of electrons or protons.
m = \(\frac{E \times c \times t}{96500}\)
∴ e = \(\frac{E}{96500}\)

→ Second law of Faraday states that, if the same quantity of electricity is passed through different electrolyte solutions or melts the amount of the different substances liberated or deposited or dissolved or had undergone reaction at the electrode are directly pro¬portional to their chemical equivalents.
\(\frac{W_1}{E_1}=\frac{W_2}{E_2}=\frac{W_3}{E_3}\)

→ A primary cell is a cell in which the electrical energy is obtained at the expense of chemical reactions. A primary cell works as long as the active chemicals reacting. The dry cell which generates a voltage of ~ 1.25 – 1.50V is an example of the primary cell.

→ A secondary cell is a cell in which the electrode reactions are reversed by the appli¬cation of an external current. Hence such a cell once used can be recharged.

→ Corrosion is a process of deterioration and consequent loss of solid metallic material through an unwanted chemical or electro-chemical attack by its environment, starting at the surface.

→ Corrosion is prevented by coating the metal surface with a thin film of paint, grease, metal (eg : Zn, Sn, Ni, Cu, Cr), metal oxide (eg: Fe₃O₄).

→ The rate of reaction is defined as the change in molar concentration of reactant or product per unit time.

→ At anytime the rate of reaction depends on the concentration of the reactants at that instant.

→ The units of rate of reaction are moles litre^-1 sec^-1 or moles litre^-1 min^-1 or moles litre^-1 hr^-1.

→ The rate of reaction is directly proportional to the (concentration of the reactants)11 or Cn.

→ For gaseous reactions the rate of reaction is directly proportional to (pressure of the reactants)”.

→ Generally rise of 10°C in temperature doubles the specific rate of reaction.

→ Catalyst increases the rate of reaction by changing the path of the reaction i.e., mak-ing the reaction to proceed in the path pf lower activation energy.

→ The mathematical expression of the rate of reaction on concentration terms of reac¬tants is known as rate expression or rate equation or rate law.

→ Units of rate constant are mole^1-n litre^n-1 sec^-1.

→ The total number of reactant molecules tak-ing part in the slowest step or rate limiting step or in the formation of intermediate species is known as molecularity of the reaction.

→ The order of a reaction is the total number of molecules whose concentrations changes during the chemical reaction or the sum of the powers of the concentration terms in the rate equation.

→ Reactions in which the rate of reaction is independent of the concentration of the reacting substances is called zero order reactions.

→ The reactions which appear to be higher order actually follow lower order Kinetics are called Pseudo Chemical reactions e.g. acid catalysed ester hydrolysis and hydrolysis of cane sugar to give glucose are pseudo first order reactions.

→ The reactions in which the products formed in the first stage may react with each other or with the original reactant to give new products are known as consecutive reactions.

→ The reactions proceeding in a series of successive reactions initiated by a suitable primary process are called chain reactions.
e.g. Formation of HCl from H₂ and Cl₂ and Chlorination of alkanes.

→ The minimum energy which must be associated with reactant molecules so that their mutual collision result in a chemical reaction is called Threshold energy.

→ Collisions which yield the product are called effective collisions or fruitful collisions or activated collisions.

→ The difference in energy between the threshold energy and the energy of the normal colliding molecules is known as activation energy.
Activation energy = Threshold energy – Energy of normal colliding molecules

→ The ratio of the rate constants at two different temperatures (preferably 35°C and 25°C) is known as temperature coefficient.

Students can go through TS Inter 2nd Year Chemistry Notes 2nd Lesson Solutions will help students in revising the entire concepts quickly.

TS Inter 2nd Year Chemistry Notes 2nd Lesson Solutions

→ A homogeneous mixture of two or more substances whose composition can be varied with certain limits is known as true solution e.g. salt in water, sugar in water, air, alloys etc.

→ Gaseous solutions are those in which solvent is gas, solute may be gas or liquid or solid. Eg:

• Gas in gas : air, mixture of O₂ and N₂
• Liquid in gas: moisture in air
• Solid in gas : camphor in air.

→ Liquid solutions are those in which solvent is liquid while solute may be gas or liquid or solid. Eg:

• Gas in liquid: aerated water, soda water
• Liquid in liquid : alcohol in water
• Solid in liquid: salt in water, sugar in water.

→ Solid solutions are those in which solvent is solid and solute may be gas or liquid or solid. Eg:

• Gas in liquid: occlusion of H₂ in palladium
• Liquid in solid : amalgams (liquid Hg in Zn)
• Solid in solid: Alloys like brass, bronze etc.

→ Mole fraction is the ratio of the number of moles of one component to the total number of moles (solute and solvent) in a binary solution.

→ In a solution, the sum of mole fraction of all components = 1

→ Molarity (M) is the number of moles of solute present in one litre of solution.

→ Normality is the number of gram equivalents of solute present in one litre of solution, represented by ‘N’.

→ Relation between molarity (M) and normality (N) of any solution are related as
Molarity × \(\frac{\text { Molecular Weight }}{\text { Equivalent Weight }}\) = Normality
Molarity = \(\frac{\text { Normality } \times \text { Equivalent Weight }}{\text { Molecular Weight }}\)

→ Henry’s law states that the mass of gas dissolving in a given amount of liquid is directly proportional to the pressure of the gas above the liquid at equilibrium.
m ∝ p or m = k.p (k is constant) k value depends on the nature of the gas, nature of the solvent,.temperature and the units of pressure.

→ Raoult’s states that partial pressure of a component (say liquid A) in solution is proportional to the mole fraction.

→ The decrease in the vapour pressure of a liquid when a non – volatile solute is dissolved in it is called the lowering of vapour pressure.

→ The ratio of the lowering of vapour pressure showing (p – pg) to the vapour pressure of the pure solvent (p) is known as the relative lowering of vapour pressure.

→ Raoult’s law states that the relative lowering of vapour pressure of a dilute solution of a non-volatile solute is equal to the mole fraction of the solute.
\(\frac{p-p_s}{p}=\frac{n}{n+N}\) where n and N are the moles of solute and solvent in a solution.

→ The properties of dilute solutions which depend on the number of particles (ions or molecules) of the solute dissolved in the solution are called colligative properties.

→ Lowering of vapour pressure, elevation of boiling point, depression in freezing point and osmotic pressure are colligative properties.

→ Since vapour pressure of a solution is less than the vapour pressure of pure solvent, the solution boils at a higher temperature than the boiling point of pure solvent and is known as elevation of boiling point.

→ Since the vapour pressure of a solution is less than the vapour pressure of pure solvent, the solution freezes at a lesser temperature than the freezing point of pure solvent and is known as depression in freezing point.

→ The inflow of solvent from a dilute solution into the concentrated solution of the solute when the two solutions are separated by a semipermeable membrane is also called as osmosis.

→ According to vant Hoff, all laws that applicable to gases are also applicable to dilute solutions and these laws are called vant Hoffs laws.

→ Solutions of same osmotic pressure at a given temperature are called isotonic solutions.

→ The molecular weights determined by using colligative properties of substances which associate or dissociate will be abnormal and are called abnormal molecular weights.

→ The ratio of the observed colligative property and calculated colligative property is called vant Hoff factor ‘i’.