We’re being asked to determine the standard enthalpy change (ΔH˚rxn) for the balanced reaction:
Recall that ΔH˚rxn can be calculated from the enthalpy of formation (ΔH˚f) of the reactants and products involved:
The ΔH˚f values: can be found in books or online:
ΔH˚f NO(g) = 90.25 kJ/mol
ΔH˚f O2(g) = 0 kJ/mol (ΔH˚f = 0 for elements in their standard state)
ΔH˚f N2(g) = 0 kJ/mol (ΔH˚f = 0 for elements in their standard state)
For each of the following reactions, calculate ΔH°rxn, ΔS°rxn, and ΔG°rxn at 25 °C. State whether or not the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 ∘C?
Part G N2(g)+O2(g)→2NO(g) Express your answer using three significant figures.
ΔH°rxn = kJ
Part H Calculate ΔS°rxn at 25 °C. Express your answer to one decimal place.
ΔS°rxn = J/K
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