Empirical formula word problem?
Washing soda, a compound used to prepare hard water for washing laundry, is a hydrate, which means that a certain number of water molecules are included in the solid structure. Its formula can be written as Na2CO3·x H2O, where x is the number of moles of H2O per mole of Na2CO3. When a 2.480 g sample of washing soda is heated at 125°C, all the water of hydration is lost, leaving 0.919 g of Na2CO3. What is the value of x?