How much 26% sulfuric acid should be mixed with 40 kg of 68% acid to obtain 32% acid concentration?

1. Let X kg be the required amount of 26% sulfuric acid.

Then sulfuric acid in solution is 26/100 and its weight is 26 * X / 100 kg.

2. The first solution was mixed with the second, in which sulfuric acid is 68/100.

Find the weight of the acid in the second solution.

40 * 68/100 = 2720/100 kg.

3. Received a solution in which the acid is 32/100 part.

The total mass of the solution is X + 40.

Acid weight (X + 40) * 32/100.

4. Received the equation.

26 * X / 100 + 2720/100 = (X + 40) * 32/100.

32 * X – 26 * X = 2720 – 1280.

6 * X = 1440.

X = 240 kg.

Answer: You will need 240 kg.