To 200 grams of a 45% acid solution was added 80 grams of water.

To 200 grams of a 45% acid solution was added 80 grams of water. Determine the mass fraction of acid in a dilute solution.

Let’s calculate how many grams of acid were in the solution. To do this, let’s make a proportion:

200 grams – 100%,

x gram – 45%.

x grams = 200 grams * 45%: 100% = 90 grams.

The first solution contained 90 grams of acid.

Let’s calculate the percentage of acid in the resulting solution, for this we will make the proportion:

280 grams – 100%,

90 grams – x%.

x = 90 grams * 100%: 280 grams = 32.14%.

The acid concentration in the resulting solution is 32.14%.

Answer: the concentration of acid in the resulting solution is 32.14%.