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