These reactions are incorrect. Here are the corrected balanced chemical equations:
Mg + CO2 -> MgO + C2Mg + CO2 -> 2MgO + C
NH4NO2 -> N2 + H2ONH4NO2 -> N2 + 2H2O
C + HNO3 -> CO2 + NO2 + H2OC + 4HNO3 -> CO2 + 2NO2 + 3H2O
These reactions are incorrect. Here are the corrected balanced chemical equations:
Mg + CO2 -> MgO + C
2Mg + CO2 -> 2MgO + C
NH4NO2 -> N2 + H2O
NH4NO2 -> N2 + 2H2O
C + HNO3 -> CO2 + NO2 + H2O
C + 4HNO3 -> CO2 + 2NO2 + 3H2O