A solution that has a K concentration of 500ppm is to be pre

A solution that has a K+ concentration of 5.00ppm is to be prepared from solid KCl. Assuming a solution density of1.000g/mL how many miligrams of KCl must be added to make 1.00L solution?

Molar mass of K: 39.10g/mol

Molar mass of KCl: 74.55g/mol

Solution

Wt. of solution in 1L = 1000gm = 1 kg; let x no. of moles of KCl is added.; wt. of K+ = 39.1x g wt of cl- = 35.45x g then we know One ppm is equivalent to 1 milligram of something per liter of water (mg/l) or 1 milligram of something per kilogram soil (mg/kg).; 5 =[wt of K+(g)/ (wt of solution + wt. of K+ + wt. of cl-)] *1000000; 5 = [39.1x/(1000g + 39.1x +35.45x) *1000000; calculating x we get; x = 1.2788 *10^-4; wt of KCl= 1.2788*10^-4 * 74.55 * 1000 = 9.533mg