Question

Show an equation and a solution for the problem. Arnold needs a 25% solution of nitric acid. He has 20 milliliters (ml) of a 30% solution. How many ml of a 15% solution should he add to obtain the required 25% solution?

Answer 1

1) x = amount of 15% solution to add
0.30(20) + 0.15x = 0.25(x+20)
6 + 0.15x = 0.25x + 5
1 = 0.10x
x = 10 add 10 mL

Answer 2

Thanks :)