Which mass of kcl would you add to water to make a 2.00 l of a 1.20-m solution?

The answer to this question would be: 179 grams

In this question you are asked to make 2l of a 1.20-m KCl solution. Then, the amount of KCl (in moles) needed would be: 1.2 mol/l * 2l = 2.4 moles

The molecular weight of KCl would be 39.0983g/mol + 35.453g/mol = 74.5513 g/mol

Then, the mass of KCl needed would be; 74.5513 g/mol * 2.4 moles = 178.92312 grams