When 13.6 grams of kcl are dissolved in enough water to create a 180-gram solution, what is the solution's concentration, expressed as a percent by mass? 4.6% kcl 6.8% kcl 7.6% kcl 8.2% kcl?

7.6% KCl

Explanation: Mass of solute is given as 13.6 grams and the mass of solution is 180 grams. The question asks to calculate the solution concentration, expressed as a percent by mass.

The formula for percent by mass is:

% by mass =

Let's plug in the values in the formula and do the calculations.

% by mass =  = 7.6%

So, the correct choice is C) 7.6% KCl.