Posted by **Harry** on Sunday, November 26, 2006 at 1:42pm.

A hydrate of strontium choloride contains 40.54% water. What is the formula of the hydrate ?

SrCl2*xH2O.

H2O = 40.54%

SrCl2 = 100 - 40.54 = 59.46%

Take 100 g sample. This gives us

59.46g SrCl2 and 40.54g H2O.

Convert to mols.

mols SrCl2 = 59.46/158.5 = 0.375

mols H2O = 40.54/18.02 = 2.25

So the formula is (SrCl_{2})_{0.375}*2.5 H_{2}O

But we want whole numbers; therefore, divide the smaller number by itself to obtain 1 (0.375/0.375 = 1.00) and divide the other number by 0.375. That should give you the whole number ratio. Post your work if you get stuck.

Thank you for your help. Yes i got the answer 6H20

Thank you for your help