Question

A container contains 20 L mixture in which there is 10% sulphuric acid. Find the quantity of sulphuric acid to be added in it to make the solution to contain 25% sulphuric acid.

• A. 3 L
• B. 4 L
• C. 2 L
• D. 5 L

Answer 1

Answer:

B. 4 L

Solution: Given: A container contains 20 L mixture, In which 10% Sulphuric acid. Calculation: According to the question The quantity of Sulphuric acid in the mixture is ⇒ 20 × 10% ⇒ 2 L The remaining quantity in the mixture is ⇒ 20 - 2 ⇒ 18 L After, adding Sulphuric acid to the mixture, the remaining quantity becomes 75% of the mixture, then The whole quantity of the mixture is ⇒ 18 × 100/75 ⇒ 24 L Now, In the mixture, the quantity of Sulphuric acid is ⇒ 24 × 25% ⇒ 6 L The quantity of Sulphuric acid added to the mixture is ⇒ 6 - 2 ⇒ 4 L ∴ The quantity of Sulphuric acid is added to the mixture is 4 L.