A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed

A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed. The dried sample weighed 52 g. The formula of the hydrated salt is: (atomic mass, Ba = 137 amu, Cl = 35.5 amu)

  1. BaCl2.H2O
  2. BaCl2.2H2O
  3. BaCl2.3H2O
  4. BaCl2.4H2O

Solution

The chemical equation for heating of hydrated barium chloride is:

BaCl2.xH2O → BaCl2 + xH2O

Weight of water (H2O) removed = 61 - 52 = 9 g

Molecular formula of H2O = 18

nH2O = 9/18 = 1/2

Molecular formula of BaCl2 = 137+(2*35.5) = 208

nBaCl2 = 52/108 = 1/4

Simplest formula = 1/4 : 1/2 = 1 : 2

Hence, BaCl2.2H2O

The correct option is B.