The hydrated salt Na2SO4. x H2O undergoes 55% loss in weight on heating and becomes anhydrous. The value of x will be

Q: The hydrated salt Na2SO4. x H2O undergoes 55% loss in weight on heating and becomes anhydrous. The value of x will be

(A) 5

(B) 3

(C) 7

(D) 10

Sol:  Percent loss of H2O in one mole of Na2SO4. x H2O

$\large = \frac{18 x \times 100}{140 + 18x} = 55$

x = 10

Ans: (D)