Question

A Chemist needs to mix a 20% acid solution with a 50% acid solution to obtain 15 liters of a 34% acid solution. How many liters of each acid solution must be used?

Answer 1

8 litres (amount of 20% solution needed) and 7 litres for (amount of 50% solution needed)

Explanation:

Let consider ‘x’ for 20% acid solution and (15 – x) for 50% acid solution. And so, the equation would be as below,

20% in x + 50% in (15 – x) = 15 litres of 34%

Convert percentage values, we get

0.20(x) + 0.50 (15 – x) = 15 (0.34)

0.20 x + 7.5 – 0.50 x = 5.1

-0.3 x + 7.5 = 5.1

0.3 x = 7.5 – 5.1

0.3 x = 2.4

`x = (2.4)/(0.3) = 8 litres (amount of 20 \% solution needed)`

Apply ‘x = 8’ value in (15 – x) we get,

15 – 8 = 7 litres

The value of 7 litres for (amount of 50% solution needed)