Ca + 2 HCl = CaCl2 + H2
M HCl = 1+35,5 = 36,5
M H2 = 2*1 = 2
2*36,5 g HCl..........2 g H2
x.............................4 kg H2
x = 146 kg HCl
c = md/ms*100
ms = 146/25 * 100 = 584 kg soluție HCl 25%
1 mol Ca.....2 g H2
y..................4 kg H2
y = 2 kmoli Ca