Problem: Consider the oxidation of NO to NO2 :NO(g) + 1/2O2(g) → NO2(g) Reactant or product  ΔH°f(kJ/mol)  S°(J/mol•K)  NO 91.3 210.8 O2 0 205.2 NO2 33.2 240.1Part ACalculate ΔG∘rxn at 25∘C. Express your answer with the appropriate units.Part BDetermine whether the reaction is spontaneous at standard conditions.

FREE Expert Solution

NO(g) + 1/2 O2(g) → NO2(g)


We’re given the ΔH˚f and S˚ of each reactant and product:

 Reactant or product 

 ΔH°f(kJ/mol) 

 S°(J/mol•K) 

 NO

 91.3

 210.8

 O2

 0

 205.2

 NO2

 33.2

 240.1


Part 1:

We can use the following equation to solve for ΔG˚rxn:


ΔG°rxn=ΔH°rxn-TΔS°rxn


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Problem Details

Consider the oxidation of NO to NO2 :

NO(g) + 1/2O2(g) → NO2(g)

 Reactant or product  ΔH°f(kJ/mol)  S°(J/mol•K) 
 NO 91.3 210.8
 O2 0 205.2
 NO2 33.2 240.1


Part A

Calculate ΔG∘rxn at 25∘C. Express your answer with the appropriate units.

Part B

Determine whether the reaction is spontaneous at standard conditions.

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