Răspuns:
a) MMg=24g/mol
MMgO=24+16=40g/mol
2×24g...............2×40g
2Mg + O2 => 2MgO
96g.....................xg
x=96×2×40/2×24=calculează
b)
n=m/M=96/24=4moli Mg
2moli...............2moli
2Mg + O2 => 2MgO
4moli................y moli
y=4×2/2=calculează