Question

Percentage of sodium sulphate $\left(N{a}_{2}S{O}_3\right)$ in hydrated salt is $50$. Hence, molecular formula of hydrated salt is $N{a}_2{S}_2{O}_3\cdot 7H_{2}O$.
If true enter 1, else enter 0.

Answer 1

Molar mass of $N{a}_2{S}_2{O}_3=126gmo{l}^{-1}$
Given, it is $50$% by mass. So,
Mass of water molecules $=126g$
Number of moles of water $=\frac{126}{18}=7$
So, compound is $N{a}_2{S}_2{O}_3\cdot 7H_{2}O$.