3.92 g of ferrous ammonium sulphate crystals are dissolved in 100 mL of water, 20 mL of this solution requires 18 mL of KMnO ₄ during titrating for complete oxidation. the weight of KMnO ₄ present in one liter of solution is :

Step-by-step solution

Normality of salt solution = 3.92 392 1 100 1000=0.1 ~N 20 mL of 0.1 N salt solution 18 ~mL of KMnO ₄ solution 20 mL of 0.1 N salt solution 18 ~mL of KMnO ₄ solution Normality of KMnO ₄ solution = 20 0.1 18 array r Normality of KMnO ₄ solution = 20 0.1 18 = 1 9 ~N array aligned Strength of KMnO ₄ solution & = 1 9 31.6 & =3.5 ~g ~L ⁻¹ aligned