Question

A tank contains weak sulfuric acid containing 15% H2SO4 and 85% H2O (by mass). If 1000 kg of 50% H2SO4 (by mass) are added to the tank and the final acid solution contains 20% H2SO4 (by mass), calculate the mass of weak acid which has been made up.

Answer 1

ANSWER :

Weak sulfuric acid contains 15% H2SO4 and 85% H2O (by mass).

Now, 1000 kg of 50% H2SO4 (by mass) are added to the tank

And, final acid solution contains 20% H2SO4 by mass.

Let x Kg of weak sulfuric acid be added to solution.

Final acid solution % = 1000 * 50% + x * 15%

20/100 = (1000* (50/100) + x * (15/100))/(1000 + x )

0.2(1000 + x ) = 1000* (50/100) + x * (15/100)

200 + 0.2x = 500 + 0.15x

0.05x = 300

5x = 30000

x =6000 Kg

Hence, mass of weak acid which has been made up = 6000 Kg