Li₂SO₃ + 2HCl = 2LiCl + SO₂ + H₂O;
<u>2Li⁺</u> + SO₃²⁻ + 2H⁺ + <u>2Cl⁻</u> = <u>2Li⁺</u><u>2Cl⁻</u> + SO₂ + H₂O;
SO₃²⁻ + 2H⁺ = SO₂ + H₂O.
2NH3=N2+3H2
3Na2+Mg3N2=2Na3N+3Mg
Na3N+3H2O=NH3+3NaOH
NH3+O2=NO+H2O
2NO+O2=2NO2
NO2+O2+H2O=2HNO3
HNO3+Ca(OH) 2=Ca(NO3)2+H2O
Ca(NO3)2=Ca(NO2) 2+O2
Mr.v=80·0.25=20g
mr-ra2=80+20=100g
w2=20/100·100%=20%