I'm a little confused about how to employ Hess's Law.
Reaction A: Mg + 2HCl --> MgCl2 +
H2 ΔH= -469
Reaction B: MgO + 2HCl --> MgCl2 + H2O ΔH= -103
Reaction C: H2 + 1/2O2 --> H2O ΔH= -285
Reaction D: Mg + 1/2O2 --> MgO ΔH= ?
Since, as we know that according to Hess's law enthalpy change will always be same whether a chemical reaction in a single... View the full answer