posted by allison .
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 2.228 g sample of washing soda is heated at 125°C, all the water of hydration is lost, leaving 0.825 g of Na2CO3. What is the value of x?
mass water expelled is
2.228-0.825 = ?, then
mols H2O = ?g/18 = ?
0.825/molar mass Na2CO3 = ?
Now find the ratio of the two. This USUALLY is done to make Na2CO3 = 1.00 and x some whole number.
the correct answer is 10 for anyone that comes here
just got it right on webassign