Răspuns:
MMgO =24+16=40g/mol
n=m/M
m=n×M=8×40=320g
MHCl =1+35,5=36,5g/mol
40g........2×36,5g
MgO + 2HCl => MgCl2 + H2O
320g.......xg
x=320×2×36,5/40= calculează
2) MH2SO4 =2×1+32+4×16=98g/mol
1mol =98g
MCO2 =12+2×16=44g/mol
m=n×M=2×44=88g
MAl2O3 =2×27+3×16=102g/mol
m=n×M=3×102=306g
