$8.0575\times 10^{-2}Kg$ of Glauber's salt is dissolved in water to obtain $1dm^3$ of a solution of density 1077.2$Kgm^{-3}$.Calculate the molarity ,molality and mole fraction of $Na_2SO_4$ in solution.

Question

$\begin{array}{1 1}(a)\;0.1M,0.15m,2.3\times 10^{-4}\\(b)\;0.2M,0.24m,4.3\times 10^{-3}\\(c)\;0.325M,0.3m,2.3\times 10^{-3}\\(d)\;0.432M,0.123m,1.3\times 10^{-5}\end{array}$