Question

0.050 kg of 4.0% (m/m) MgCl2

the answer is 2.0g MgCl2

how do you show the work

Answer 1

It would help if you asked a question. There is none here. Do you want grams MgCl2? If you have 0.050 kg solution that is 0.050 kg x (1000g/kg) = 50 g solution. If that is 4% MgCl2, then 50g solution x 0.04 = 2 g MgCl2