Answer:
The water of crystallization of the intermediate analyte is 5.
Seeing as the question does not provide the value for weight of the salt on further heating (at 120° C), you can apply the steps in this explanation to attain that value.
Explanation:
XSO4.7H2O → XSO4 + 7H2O
8.1g 4.9g
8.1 - 4.9 = 3.9g of water evaporated
The ration of water to salt is:
XSO4 : H2O
grams : 4.9 3.2
moles: 72 + 32 + (16×2)=136 (1×2)+ 16= 18
[tex]\frac{4.9}{136}[/tex] [tex]\frac{3.2}{18}[/tex]
0.036 0.178 (divide both sides by smallest value)
1 4.93
∴ water of crystallization of intermediate is 5.