# 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 Na2 CO3 xH2 O, where x is the number of moles of H2 O per mole of Na2 CO3. When a 2.814 -g sample of washing soda is heated at 25 oC, all the water of hydration is lost, leaving 1.04 g of Na2 CO3.What is the value of x?

###### FREE Expert Solution

We’re asked to determine the value of x in washing soda, (Na2CO3•xH2O)if heating a 2.814 -g sample leaves 1.04 g of Na2CO3.

Recall that hydrates such as washing soda lose its water of hydration upon heating

This means that to solve for x which is the number moles of H2O per mole Na2CO3we need to do the following steps:

Step 1: Determine the mass of water of hydration, H2O evaporated :

Mass H2O = Na2CO3•xH2O -  mass Na2CO3

Step 2: Determine the moles of H2O and Na2CO3 to solve for x

85% (52 ratings) ###### Problem Details

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 Na2 CO3 xH2 O, where x is the number of moles of H2 O per mole of Na2 CO3. When a 2.814 -g sample of washing soda is heated at 25 oC, all the water of hydration is lost, leaving 1.04 g of Na2 CO3.

What is the value of x?