A sample that has the formula MgCl2.6H2O loses a portion of water when it is dried in an oven but undergoes no other changes. If the student started with 10.000 g of the compound, and ends with a residue that weighs 7.342 g whats the formula of the residue?
a. MgCl2.H2O
b. MgCl2.2H2O
c. MgCl2.3H2O
d. MgCl2.4H2O
e. MgCl2.5H2O