Răspuns:
MCa =40g/mol
n=2/40=0,05 moli Ca
a)
1mol............2moli
Ca + 2H2O => Ca (OH)2 + H 2
0,05 moli....ymoli
y=0,05×2/1=0,1 moli H2O
b)
MCa(OH)2=40+2×16+1×1=74g/mol
40g..................................74g
Ca + 2H2O => Ca (OH)2 + H 2
2g...............................xg
x= 2×74/40=3,7 g Ca(OH)2