Question

0.20 g of a diacidic base require 25ml of HCl for exact neutralisation.What is the molecular mass of the base.

Answer 1

here the equation of reaction is; M(OH)2+Acid→salt + water 0.20g + 25ml That is ; 0.20 g of base needs 25 ml of HCl. 25 ml acid = 25/22400 =0.00116 moles of acid. ie, 0.20g reacts with 0.00116 moles of acid. there for mass of base needed to react with 1 mole of acid= (1/0.00116)*0.2=17.92 g we know that 1 mole of base reacts with 1 mole of acid to form salt and water. so mass of one mole of base is its molecular mass ie; molecular mass= 17.92 g