How many liters of a 2% acid solution must be added to 30 liters of a 10% acid solution to dilute it to an 8% acid solution

10 liters.

Step-by-step explanation:

Let the volume of 2% acid be x liters.

Then the volume of the 8% solution will be (x + 30) liters.

Work in amounts of pure acid: amount of acid in the 10% solution = 30 * 0.1

= 3. So we have the equation:

0.02x + 3 = 0.08 (x + 30)

0.08x - 0.02x = 3 - 0.08*30

0.06x = 0.6

x = 10

So the answer is 10 liter of the 2% solution.