How much do you need to mix 15% and 25% hydrochloric acid solutions to get 300 g of a 22% solution?

First, we find the mass of the substance in the resulting solution.

We multiply the weight of the solution by the percentage.

We get:

300 * 22% / 100% = 300 * 0.22 = 66 grams.

Let’s say that the weight of the first solution is x grams, and the second is in grams.

Thus, we get the following system of equations:

x + y = 30.

0.15 * x + 0.25 * y = 66.

Express the x value from the first equation.

x = 300 – y.

Substitute this value into the second equation.

0.15 * (300 – y) + 0.25 * y = 66.

45 – 0.15 * y + 0.25 * y = 66.

0.1 * y = 21.

y = 21 / 0.1 = 210 grams (second solution).

x = 300 – 210 = 90 g (first solution).

Answer: 90 and 210 grams.