Question

a chemist has 100 ml of a solution that is 8% acetic acid. if the chemist adds 50 ml of pure water to this solution, what is the percent concentration of the resulting mixture?

Explanation:

Step1: Calculate amount of acetic - acid

The initial solution is 120 ml and is 6% acetic - acid. The amount of acetic - acid is $120\times0.06 = 7.2$ ml.

Step2: Calculate total volume of new mixture

The chemist adds 80 ml of pure water to the 120 - ml solution. The total volume of the new mixture is $120 + 80=200$ ml.

Step3: Calculate percent concentration of new mixture

The percent concentration of acetic - acid in the new mixture is $\frac{7.2}{200}\times100\% = 3.6\%$.

Answer:

3.6%