A 0.954-gram sample of hydrated magnesium sulfate,MgSO₄∙ xH₂O,is heated until all of the water is driven off.If 0.465 grams of anhydrous MgSO₄ is obtained,how many water molecules combine with each formula unit of magnesium sulfate in the hydrate?

Question

Quizplus · Accepted Answer

The mass of water lost is 0.954 g - 0.465 g = 0.489 g. The molar mass of water (H2O) is 18.015 g/mol, and the molar mass of MgSO4 is 120.366 g/mol. The moles of MgSO4 are 0.465 g / 120.366 g/mol = 0.00386 mol. The moles of water are 0.489 g / 18.015 g/mol = 0.02714 mol. The ratio of moles of water to moles of MgSO4 is approximately 7, indicating 7 water molecules per formula unit.

A 0954-Gram Sample of Hydrated Magnesium Sulfate,MgSO4∙ XH2O,is Heated Until All

A 0954-Gram Sample of Hydrated Magnesium Sulfate,MgSO₄∙ XH₂O,is Heated Until All