To prepare a solution of 100 mg per liter available chlorine, how much of 5.25 percent bleach should be used with one gallon of water?

To determine how much of 5.25 percent bleach is needed to achieve a solution with 100 mg of available chlorine per liter, it is essential to first understand the concentration of available chlorine in the bleach.

5.25 percent bleach contains 5.25 grams of available chlorine per 100 milliliters. To convert this to a per-liter basis, you can multiply by 10 since there are 1,000 milliliters in a liter. This indicates that there are 52.5 grams of available chlorine in 1 liter of 5.25 percent bleach.

Next, to find out how many liters of this bleach are required to achieve a concentration of 100 mg of available chlorine, first convert 100 mg to grams. This is equivalent to 0.1 grams. The calculation then involves finding out how much of the bleach solution contains this amount of chlorine.

Using the concentration of 52.5 grams per liter, set up the equation:

(amount of bleach in liters) x 52.5 grams = 0.1 grams

From this, you can find the amount of bleach needed:

amount of bleach in liters = 0.1 grams / 52.5 grams/liter