Answer to Question #109387 in General Chemistry for Rodaina

Question

13. How many litres of a 12% sulphuric acid solution should be mixed with 5L of a 2% sulphuric acid solution to obtain a 8% solution of sulphuric acid?

Answer 1

Let $x$ litres of a 12% sulphuric acid solution should be mixed with 5L of a 2% sulphuric acid solution to obtain a 8% solution of sulphuric acid.

Concentration of mixture $=8=(12*x+2*5)/(x+5)$

$\implies 8x+40=12x+10 \implies 3x=30 \implies x=10L$

Thus, 10 litres of a 12% sulphuric acid solution should be mixed with 5L of a 2% sulphuric acid solution to obtain a 8% solution of sulphuric acid.