Chemistry - Liquid Solution Question with Solution | TestHub

Given, molarity of solution $=2$ Volume of solution $=250\mathrm{mL}=\frac{250}{1000}=\frac{1}{4}\mathrm{L}$ Molar mass of $${\mathrm{HNO}}_3=1+14+3\times 16=63\mathrm{g}{\mathrm{mol}}^{-1}$$ $\because$ Molarity $$\begin{array}{rl}& =\frac{\text{ weight of }{\mathrm{HNO}}_3}{\text{ mass of }{\mathrm{HNO}}_3\times \text{ volume of solution ( }L)}\\ & \therefore \text{ Weight of }{\mathrm{HNO}}_3=\text{ molarity }\times \text{ mol. mass }\\ & \times \text{ volume }(\mathrm{L})\\ & =2\times 63\times \frac{1}{4}\mathrm{g}=31.5\mathrm{g}\\ & \end{array}$$ It is the weight of $100\%{\mathrm{HNO}}_3$. But the given acid is $70\%{\mathrm{HNO}}_3$. $$\therefore \text{ Its weight }=31.5\times \frac{100}{70}\mathrm{g}=45\mathrm{g}$$