What is the percent by mass concentration of KCl in a solution prepared by adding 80 grams KCl to 200 grams of water?

mass solute = 80g

mass soln = 200g + 80g = 280g
%by mass = (80/280)*100 = ?

To calculate the percent by mass concentration of KCl in the solution, we need to divide the mass of KCl by the total mass of the solution and then multiply by 100.

Step 1: Calculate the total mass of the solution.
Total mass of the solution = mass of KCl + mass of water
Total mass of the solution = 80 grams + 200 grams
Total mass of the solution = 280 grams

Step 2: Calculate the percent by mass concentration of KCl.
Percent by mass concentration of KCl = (mass of KCl / total mass of the solution) x 100%
Percent by mass concentration of KCl = (80 grams / 280 grams) x 100%
Percent by mass concentration of KCl = 0.2857 x 100%
Percent by mass concentration of KCl = 28.57%

Therefore, the percent by mass concentration of KCl in the solution is 28.57%.

To calculate the percent by mass concentration of KCl in a solution, we need to first determine the mass of KCl in the solution, and then divide it by the total mass of the solution, and finally multiply by 100 to express the concentration as a percentage.

Step 1: Calculate the mass of KCl in the solution.
Given that the mass of KCl added is 80 grams, we have the mass of KCl in the solution.

Step 2: Calculate the total mass of the solution.
The mass of water added is 200 grams. Since we are interested in the total mass of the solution, we add the mass of KCl (80 grams) to the mass of water.

Total mass of the solution = mass of water + mass of KCl = 200 grams + 80 grams = 280 grams.

Step 3: Calculate the percent by mass concentration of KCl.
Finally, we divide the mass of KCl by the total mass of the solution, and multiply by 100.

Percent by mass concentration of KCl = (mass of KCl / total mass of the solution) x 100
= (80 grams / 280 grams) x 100
= 28.57%

Therefore, the percent by mass concentration of KCl in the solution prepared by adding 80 grams of KCl to 200 grams of water is approximately 28.57%.