A 90.00 g sample of Na, CO *xH, O is heated until all of the water is driven off, forming 32.28 g of the anhydrous salt, Na, Coz. What is the percent by
mass of H, O in the hydrated compound, Na CO, *xH, O?*

The percent by  mass of H₂O in the hydrated compound, Na₂CO₃.xH₂O = 64.13%

Given

90 g sample Na₂CO₃.xH₂O

32.28 g Na₂CO₃

Required

The percent by  mass of H₂O

Solution

mass of H₂O = mass of sample - mass of the anhydrous salt, Na₂CO₃

The percent by mass :