Problem: 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 J 2 KClO3(s)→2KCl(s)+3 O2(g) Express your answer to one decimal place.ΔH∘rxn = kJPart K Calculate ΔS°rxn at 25 °C. Express your answer to one decimal place.ΔS∘rxn = J/K

FREE Expert Solution

We’re being asked to determine the standard enthalpy change (ΔH˚rxn) for the balanced reaction:

2 KClO3(s)→2KCl(s)+3 O2(g)


Recall that ΔH˚rxn can be calculated from the enthalpy of formation (ΔH˚f) of the reactants and products involved:

ΔH°rxn=ΔH°f, prod-ΔH°f, react


The ΔH˚f values: can be found in books or online:

ΔH˚f KCl(s) = -436.75  kJ/mol
ΔH˚f KClO3(s) = -397.73  kJ/mol
ΔH˚f O2(g) 0 kJ/mol (ΔH˚f = 0 for elements in their standard state)

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Problem Details

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 J 2 KClO3(s)→2KCl(s)+3 O2(g) Express your answer to one decimal place.

ΔH∘rxn = kJ

Part K Calculate ΔS°rxn at 25 °C. Express your answer to one decimal place.

ΔS∘rxn = J/K

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