A solution was prepared by dissolving 25.0 g of kcl in 225 g of water. calculate the mass percent of kcl in the solution.

To calculate the percent mass of a molecule, you need to divide its mass with the total mass of the solution. The solution prepared in this question is made by dissolving 25.0 g of KCl in 225 g of water, which will make a solution with a total mass of : 25+225 = 250 g.

The mass percent of KCl mass would be: 25g / 250g = 10%