What is the percent by mass of chlorine in potassium chloride? Chemistry The Mole Concept Percent Composition 1 Answer anor277 Jul 8, 2016 In #KCl#? Approx #50%# Explanation: #%Cl# #=# #"Mass of chlorine"/"Mass of potassium chloride"xx100%# #=# #(35.45*g*mol^-1)/(74.55*g*mol^-1)xx100%=??%# Answer link Related questions What is mole percent? Question #e2e8b Question #bc737 Question #bc73b Question #e2e8f Question #b9857 Question #b985b Question #fee41 Question #c5c01 Question #bc73f See all questions in Percent Composition Impact of this question 6579 views around the world You can reuse this answer Creative Commons License