Question

In what ratio (by mass) should a 90% solution of $H_{2}S{O}_4$ be mixed with a 10% solution of the acid to obtain a 40% solution?

• A. 5:3
• B. 3:4
• C. 3:5
• D. 4:5

Answer 1

The correct option is C 3:5

Let x g of 90% $H_{2}S{O}_4$ be mixed with y g of 10% $H_{2}S{O}_4$ to obtain (x+y) g 40% $H_{2}S{O}_4$.
So, $\frac{x\times 0.9+y\times 0.1}{x+y}\times 100=40$
$\Rightarrow \frac{x}{y}=\frac{0.3}{0.5}=\frac{3}{5}$