Răspuns:
a. 20+2×17=54
b. 1:2
c. te uiti in sistem si iei de acolo masele lor atomice ca:o:h=40:16:1
d. 54g.....20gca......32go.....2gh
100....a...............b........c
scoti cu regula de 3 simpla
e. 2 moli de baza? rescrie cerinta
x 2 moli
2HCl + Ca(OH)2 2H2O+ CaCl2
2 moli 1 mol
scoti x=4 moli
md=x(niu)•36.5(masa molara HCl)=146 g
c=md•100/ms scoti ms=md×100/c=730g