{"id":35439,"date":"2022-11-23T11:54:52","date_gmt":"2022-11-23T06:24:52","guid":{"rendered":"https:\/\/tsboardsolutions.com\/?p=35439"},"modified":"2022-11-23T11:54:52","modified_gmt":"2022-11-23T06:24:52","slug":"ts-inter-2nd-year-chemistry-notes-chapter-11","status":"publish","type":"post","link":"https:\/\/tsboardsolutions.com\/ts-inter-2nd-year-chemistry-notes-chapter-11\/","title":{"rendered":"TS Inter 2nd Year Chemistry Notes Chapter 11 Haloalkanes and Haloarenes"},"content":{"rendered":"
Students can go through TS Inter 2nd Year Chemistry Notes<\/a> 11th Lesson Haloalkanes and Haloarenes will help students in revising the entire concepts quickly.<\/p>\n \u2192 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.<\/p>\n \u2192 Halogen compounds containing sp3<\/sup> C – X bond (X = F, Cl, Br, I) include Alkyl halides (haloalkanes), Allylic halides and Benzylic halides.<\/p>\n \u2192 Alkyl halides are further classified as pri-mary (1\u00b0). secondary (2\u00b0) or tertiary (3\u00b0) according to the nature of the carbon to which the halogen is attached.<\/p>\n \u2192 Halogen compounds containing sp2<\/sup> C – X bond include Vinylic halides and Aryl halides.<\/p>\n \u2192 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.<\/p>\n \u2192 Since halogen atoms are more electronegative than carbon, the carbon-halogen bond of alkyl halide is polarised.<\/p>\n \u2192 C – X bond length increases from C – F to C – I.<\/p>\n \u2192 Alkyl halides are prepared from alcohols on reaction with concentrated halogen acids (HX), PCl3<\/sub>, PCl5<\/sub> Or SOCl2<\/sub>.<\/p>\n \u2192 Free radical chlorination or bromination of alkanes gives a complex mixture of isomeric mono and polyhaloalkanes. \u2192 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<\/sub> or SbCl5<\/sub>. \u2192 When an aromatic primary amine reacts with nitrous acid (NaNO2<\/sub> + HX) at 0 – 5\u00b0C, 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.<\/p>\n <\/p>\n \u2192 When diazonium salt solution is shaken with KI solution the diazonium group is replaced by iodine.<\/p>\n \u2192 Addition of bromine in CCl4<\/sub> 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.<\/p>\n \u2192 Alkyl fluoride is prepared by heating an alkyl chloride or bromide in the presence of a metallic fluoride such as AgF2<\/sub>, Hg2<\/sub>F2<\/sub> etc (swarts reaction). \u2192 Haloalkanes are only very slightly soluble in water.<\/p>\n \u2192 The chemical reactions of haloalkanes may be divided into three categories.<\/p>\n \u2192 The order of reactivity of alkyl halides towards SN<\/sub>1<\/sup> and SN<\/sub>2<\/sup> reactions is as follows :<\/p>\n \u2192 A carbon atom joined to four different atoms or groups is called an asymmetric carbon or stereocentre or chirality centre.<\/p>\n \u2192 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.<\/p>\n \u2192 Optical activity is the ability of a chiral sub-stance to rotate the plane of plane-polarised light.<\/p>\n \u2192 The three dimensional arrangement of atoms or groups at a chirality centre is called the absolute configuration.<\/p>\n \u2192 The stereoisomers related to each other as non-superimposable mirror images are called enantiomers.<\/p>\n \u2192 SN<\/sub>2<\/sup> reactions of optically active alkyl halides are accompanied by inversion of configuration.<\/p>\n \u2192 SN<\/sub>1<\/sup> reactions of optically active alkyl halides are accompanied by racemisation.<\/p>\n \u2192 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”.<\/p>\n \u2192 Alkyl magnesium halides (RMgX) are known as Grignard reagents.<\/p>\n <\/p>\n \u2192 A number of polyhalogen compounds e.g., dichloromethane, chloroform, iodoform, CCl4<\/sub>, freon and DDT have many industrial applications.<\/p>\n \u2192 Chloroform is slowly oxidised by air in the presence of light to a very poisonous gas, carbonyl chloride, also known as phosgene, COCl2<\/sub>. Hence chloroform is stored in closed amber coloured bottles completely filled so that air is kept out.<\/p>\n \u2192 Dichlorodifluoro methane (CCl2<\/sub>F2<\/sub>) is known as Freon 12.<\/p>\n \u2192 Paul Muller discovered the effectiveness of DDT as an insecticide.<\/p>\n","protected":false},"excerpt":{"rendered":" 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 \u2192 Alkyl\/aryl halides may be classified as mono, di or polyhalogen (tri-tetra, etc) compounds depending upon whether they contain one, … Read more<\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[26],"tags":[],"yoast_head":"\nTS Inter 2nd Year Chemistry Notes 11th Lesson Haloalkanes and Haloarenes<\/h2>\n
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\nCH3<\/sub>Br + AgF \u2192 CH3<\/sub>F + AgBr<\/p>\n\n
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