Răspuns:
1.
MMgO=24+16=40g/mol
MHCl =1+35,5=36,5g/mol
n=m/M
m=40×8=320gMgO
40g......2×36,5g
MgO +2 HCl => MgCl2 + H2O
320g.....xg
x=320×2×36,5/40=calculează
2. MH2SO4 =2×132+4×17=98g/mol
1mol H2SO4 =98g
MCO2=12+2×16=44g/mol
m=2×44=88g
MAl2O3 =2×27+3×16=102g/mol
m=3×102=306g
