What is the formula of the hydrate?

Question

A 41.87 gram sample of a hydrate of BeSO₄ was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 24.84 grams of the anhydrous compound remained.

Answer 1

Molar mass of H₂O = 18 g/mol

Molar mass of BeSO₄ = ( 9 + 32 + (16 * 4)) g/mol = 105 g/mol

Molar mass of BeSO₄.xH₂O = (105 + 18x) g/mol

Moles of BeSO₄ = mass/molar mass = 24.84/105 = 0.237 mol

Molar mass = mass/moles

105 + 18x = 41.87/0.237

105 + 18x = 176.67

18x = 71.67

x = 3.98 (closest whole number is 4)

x ~ 4

The formula of the hydrate is BeSO₄.4H₂O