Molality of $0.8 \ M \ H_2SO_4$ solution (density $1.06 \ g \ cm^{-3}$) is . . . . . . $\times 10^{-3} \ m$.

If $80 \ g$ of copper sulphate $CuSO_{4} \cdot 5H_{2}O$ is dissolved in deionised water to make $5 \ L$ of solution. The concentration of the copper sulphate solution is $x \times 10^{-3} \ mol \ L^{-1}$. The value of $x$ is .... .
[Atomic masses: $Cu = 63.54 \ u, S = 32 \ u, O = 16 \ u, H = 1 \ u$]

How many grams of ethanol must be added to $1.0 \ kg$ of water to have a mole fraction of ethanol equal to $0.2$?

Calculate the mass of sodium acetate $(CH_3COONa)$ required to make $500 \ mL$ of a $0.375 \ M$ aqueous solution. The molar mass of sodium acetate is $82.0245 \ g \ mol^{-1}$. (in $g$)

Concentrated $HCl$ is $10 \,N$. How can $1000 \,cc$ of $1 \,N \,HCl$ be prepared by dilution?

If $2 \ g$ of $NaOH$ is dissolved to make $200 \ mL$ solution at $25^{\circ} C$, the molarity $(M)$ at $90^{\circ} C$ is