Ответ:
Na2S+FeSO4=FeS+Na2SO4
2Na⁺+S²⁻+Fe²⁺+SO4²⁻=FeS+2Na⁺+SO4²⁻
S²⁻+Fe²⁺=FeS
Na2S+2HCl=2NaCl+H2S↑
2Na⁺+S²⁻+2H⁺+2Cl⁻=2Na⁺+2Cl⁻+H2S↑
S²⁻+2H⁺=H2S↑
2NH4Cl+Ca(OH)2=CaCl2+2NH3↑+2H2O
2NH4⁻+2Cl⁻+Ca²⁺+2OH⁻=Ca²⁺+2Cl⁻+2NH3↑+2H2O
2NH4⁻+2OH⁻=2NH3↑+2H2O
Ответ:
Na2S+FeSO4->Na2SO4+FeS
Na2S+2HCl->2NaCl+H2S
Pb(NO3)2+@NaI->2NaNO3+PbI2