What is the percentage of water in hydrated calcium chloride

24.5%

Explanation:

You just add up the atomic masses.  

Ca - 40.078  

Cl2 - 35.4527 x 2 = 70.9054  

110.9834  

H4 - 1.00794 x 4 = 4.03176  

O2 - 31.9998  

36.03056  

TOTAL - 147.01396  

So the water is 36.03056/147.01396 = .245082576 but that is only accurate to three decimals (because the mass of Ca was only given to three decimals) so we write .245 and that is 24.5%

This is not my answer but I found it on Yahoo answers and it was answered by Anonymous.

24.5%

Explanation: Molar mass of CaCl2 * 2 H2O = 40.078 + ( 2 x 35.453) + ( 2 x 18.02)=147.024 g/mol  

% H2O = 2 x 18.02 x 100/ 147.024 =24.5

56 moles of   lieter in chemistry