Mg + 2 HCl = MgCl2 + H2
M Mg = 24 g/mol
M HCl = 36,5 g/mol
24 g Mg.......2*36,5 g HCl
100 g Mg................x
x = 304,166 g HCl
c = md*100/ms
ms = 304,166*100/20 = 1520,83 g soluție HCl
24 g Mg........1 mol MgCl2
100 g Mg...............x
x = 4,166 moli MgCl2