The Compound MgSo4.xH2o is found to contain 51.2% by weight of water of crystallisation. What will be x ?

Asked by Amyra B | 29th Oct, 2014, 07:22: AM

Expert Answer:

MgSO4 = 24 + 32 + 16*4 = 120g/mol 
=> MgSO4.xH2O = 120 + 18x g/mol 

The percentage of water is 51.2% 
=> 18x/(120 + 18x) = 51.2/100 => 1800x = 51.2*(120 + 18x) 

x is 6.99 ≈ 7 

Hence, the formula is MgSO4.7H2O

Answered by Prachi Sawant | 29th Oct, 2014, 11:03: AM