A solution of ferrous chloride used at a pretreatment facility contains 30 percent ferrous chloride and has a density of 1.33 g/mL. How many grams of ferrous chloride are in one liter of the solution?

To determine the amount of ferrous chloride in one liter of the solution, we start by considering the density and the concentration of the solution.

First, the density of the solution is given as 1.33 grams per milliliter, which means 1 liter (1000 mL) of this solution weighs:

1.33 g/mL x 1000 mL = 1330 grams.

Next, since the solution has a concentration of 30 percent, this means that 30% of the total weight of the solution is ferrous chloride. Therefore, the mass of ferrous chloride in the solution can be calculated by finding 30% of the total mass of the solution:

0.30 x 1330 grams = 399 grams.

Thus, one liter of the solution contains 399 grams of ferrous chloride.

This leads to the conclusion that the correct answer, which reflects the calculated amount of ferrous chloride in one liter of the solution, is indeed 399 grams per liter.