Question

pure acid is to be added to a 5% acid solution to obtain 95L of 16% solution. what amounts of each should be used? How many Liter of 100% pure acid should be used to make a solution?

Answer 1

I'd suggest that you immediately represent the number of liters of pure acid by x or some other appropriate variable. You could let y represent the number of liters of the 5% acid solution on hand before any pure acid is added to it.

Answer 2

So, if you add x liters of pure acid to y liters of the 5% solution, how many liters total will you then have? That, essentially, is what this homework problem is asking you.

Unfortunately, this single equation alone is insufficient to provide the values of x and y. We need an additional equation. Think in terms of how much pure acid we have before and after mixing the pure acid and the 5% solution.

Can you come up with an equation that represents pure acid only, using the 5% and 16% percentages given, and also involving the volumes x and y?