Question

In a school chemistry lab, the lab assistant has two bottles of acid solution on his shelf:

• Solution A: 55% acid concentration
• Solution B: 80% acid concentration

The science teacher wants 60% a acid solution for tomorrow's experiment that is to be used by the students.

In what ratio should the 55% solution and the 80% solution be mixed to obtain a 60% acid solution?

Answer 1

Let x be the quantity of 55% solution and y be the quantity of 80% solution.

Required concentration of solution by mixing two solutions = 60%.

∴ 55x + 80y = 60(x + y)

⇒ 55x + 80y = 60x + 60y

⇒ 55x − 60x + 80y − 60y = 0

⇒ −5x + 20y = 0

⇒ 20y = 5x

⇒ `x/y = 20/5`

⇒ `x/y = 4/1`

⇒ x : y = 4 : 1.

Hence, the ratio of 55% solution to 80% solution is 4 : 1.