Question

A 45.61 gram sample of a hydrate of Ba(ClO4)2 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 39.90 grams of the anhydrous compound remained. What is the formula of the hydrate?

Answer 1

Ans :

Mass of water lost = mass of hydrate compound - mass of anhydrate compound

= 45.61 g - 39.90 g

= 5.71 g

number of mol of water = mass / molar mass

= 5.71 g / 18.01528 g/mol

= 0.317 mol

mol of anhydrous Ba(ClO4)2 = mass / molar mass

= 39.90 g / 336.24 g/mol

= 0.119 mol

Ratio of moles = 3: 1

So the formula of hydratte will be : Ba(ClO4)2.3H2O