Răspuns:
2Na + Cl2= 2NaCl
2Mg + O2=2 MgO
H2O + MgO= Mg(OH)2
SO3 + H2O= H2SO4
H2O + CO2 ⇄H2CO3
a= Cl2
b= O2
d= MgO
e = H2CO3
f=SO3
MgO
MMgO=24+16=40g/mol
r.at Mg:O=1:1
r.m.Mg:O=24:16=3:2
H2CO3
MH2CO3=1×2+12+3×16=62g/mol
r.at.H:C:O=2:1:3
r.m H:C:O=2:12:48=1:6:24
SO3
MSO3=32+3×16=80g/mol
r.at. S:O=1:3
r.m S:O=32:48=2:3
Explicație: