Question

A 70% solution (solution 1) of $H_{2}S{O}_4$ is mixed with a 40% solution (solution 2) of the acid to obtain a 60% solution (solution 3). If solution 1 and solution 2 are mixed in a ratio (by mass) of $x:1$, the value of $x$ is

Answer 1

Let $x$ g of 70% $H_{2}S{O}_4$ be mixed with y g of 40% $H_{2}S{O}_4$ to obtain $(x+y)$ g 60% $H_{2}S{O}_4$.
So, $\frac{x\times 0.7+y\times 0.4}{x+y}\times 100=60$
$\Rightarrow \frac{x}{y}=\frac{0.2}{0.1}=\frac{2}{1}$