Here students can locate TS Inter 1st Year Chemistry Notes 5th Lesson Stoichiometry to prepare for their exam.
TS Inter 1st Year Chemistry Notes 5th Lesson Stoichiometry
→ The standard reference for relative atomic masses is Carbon – 12.
→ \(\frac{1}{12}\)th of the mass of C -12 is called atomic 12 mass unit (amu).
→ The value of amu is 1.66 × 10-24 gm. This is known as Avogram.
→ The weight of a substance in grams, numerically equal to its molecular weight is called gram molecular weight or gram mole.
→ Number of atoms present in one gram molecular weight of element is called Avogadro’s number. Its value is 6.023 × 1023.
→ The volume occupied by one gram molecular weight of a gas at STP is called gram molar volume (GMV). Its value is 22.4 lits or 22,400 cc.
→ Mole is the SI unit for the amount of a substance.
→ Mole is that mass of a substance which contains Avogadro number of structural units.
→ The apparent charge that an atom appears to have in its combined state is called its oxidation number. It may be + ve (or) – ve (or) fractional or zero.
→ The element that never exhibits + ve oxidation number is Fluorine.
→ The process of removal of electron is called Oxidation.
→ The process of addition of electron is called Reduction.
→ The substance which gains electrons is called Oxidant.
→ The substance which loses electrons is called Reductant.
→ A chemical reaction which involves both oxidation and reduction is called redox re-action.
→ Redox reactions can be balanced by
(a) Ion electron method
(b) Oxidation number method.
→ The actual masses of substances conveyed by a balanced equation is known as Stoichiometry.
→ One hundred times to the weight ratio of an element and the compound containing the element is called percentage composition of the element.
→ The formula that gives the simplest ratio of atoms of the constituent elements present in a compound is called empirical formula.
→ The formula that gives the exact number of atoms of the constituent elements present in a compound is called Molecular formula.
→ Molecular formula = Empirical formula × n
where, n = \(\frac{\text { Molecular formula weight }}{\text { Empirical formula weight }}\)
→ Increase in oxidation number is oxidation and decrease in oxidation number is reduction.