Question

a mixture of KCl and KNO3 is 44.2% potassium by mass. The percent of KCL in the mixture is?

Answer 1

Given,

mixture = KCl + KNO3

each gives 1 K

mass % K = 44.2%

mass KCl = 74.55 g

mass KNO3 = 101.10 g

mass% K in KCl = 39.1 g x 100/74.55 g = 52.45%

mass% K in KNO3 = 39.1 g x 100/101.10 g = 38.7%

Now,

let say we have x fraction amount of KCl in the mixture,

then we would have 1-x fraction amount of KNO3 left in the mixture

that is,

52.45x + 38.7(1-x) = 44.2

solving,

52.45x+ 38.7 - 38.7x = 44.2

x = (5.5/13.75) = 0.4 fraction

the percent KCl in the mixture = 0.4 x 100 = 40%