Calculate the mass of #KCl# that should be dissolved to form a 5 ppm #Cl^-# ion solution having a total volume of 20 #dm^3#?

1 Answer
Jul 17, 2015

Answer:

The mass of KCl is 0.2 g.

Explanation:

#"5 ppm"# means #"5 g of solute"# in #10^6 "g of solution"#.

#"Mass of soln" = 20 cancel("dm³ soln") × "1000 g soln"/(1 cancel("dm³ soln")) = "20 000 g soln"#

#"Mass of Cl"^(-) = 20 000 cancel("g soln") × ("5 g Cl"^-)/(10^6 cancel("g soln")) = "0.10 g Cl"^-#

#"Mass of KCl" = 0.10 cancel("g Cl⁻")× "74.55 g KCl"/(35.45cancel("g Cl⁻")) = "0.2 g KCl"#