The reaction shown below has a negative enthalpy change and a positive entropy change. 2O3 (g) yields 3O2 (g) Which of the following best describes this reactio

Question

The reaction shown below has a negative enthalpy change and a positive entropy change.
2O3 (g) yields 3O2 (g)
Which of the following best describes this reaction?
The reaction will only be spontaneous at high temperatures.
The reaction will only be spontaneous at low temperatures.
The reaction will not be spontaneous at any temperature.
The reaction will be spontaneous at any temperature.

Answer 1

Hello Billy

 

The thermodynamic property for a reaction to be spontaneous is defined by the value of Gibb's free energy (ΔG).

 

The relationship between ΔG and the enthalpy and entropy of a system can be expressed by the equation:

 

ΔG = ΔH - TΔS

 

where ΔH is the enthalpy change and ΔS is the change in entropy.

 

Since your question states the conversion of 2 O₃ (g) → 3 O₂ (g) has a negative ΔH value and a positive ΔS value, the only condition for ΔG to be negative is at a high temperature (answer choice "b").