Calculate the concentration of potassium ions in the solution, in mol L^-1. Each 200 mL of an electrolyte solution designed for treating dehydration contains 0.47 g of sodium chloride (NaCl), 0.30 g of potassium chloride (KCl) and 3.56g of glucose (C6H12O6).
You have 0.30 g of KCl in 200 mL, so you have 5 times as much in one liter.
0.3 * 5 = 1.5 g/liter.
To determine # of moles, divide actual mass by formula mass of KCl.
formula mass of KCl = atomic mass of K + atomic mass of Cl.
You now know the # of moles of KCl in solution. The # of moles of K ion and the number of moles of Cl ion is the same as the number of moles of KCl.