How many grams of KOH should be dissolved in water to make 2000.0 grams of a 10.0 ppm solution?

We need 2 * 10^-2 grams (=0.02 grams) KOH

Explanation:

Step 1: Data given

Mass of solution = 2000.0 grams

Solution = 10.0 ppm

Step 2: Calculate mass KOH needed

A solution's concentration in parts per million tells you the number of grams of solute present for every 10^6 grams of the solution.

In this case, the target solution must have a concentration of

10.0 ppm, what means that it must contain 10.0 g of KOH (the solute), for every 10^6 grams of the solution

This means that the mass of KOH needed to make this solution is equal to

2000 grams * 10 grams KOH / 10^6 grams solution = 0.02 = 2 * 10^-2 grams

So, if you dissolve 2 * 10^-2 grams of KOH in enough water to get a total mass of the solution to 2000.0 g, you will have a 10.0-ppm KOH solution.