Question

Explain qualitatively how DG changes in each of the following reactions as the partial pressure of O₂ is increased:

(a) 2CO(g) + O₂ (g) ® 2CO₂(g)

(b) 2H₂O₂ (l) ® 2H₂O(l) + O₂(g)

( c) 2KClO₃(s) ® 2KCl(s) + 3O₂(g)

Answer 1

Let us first look at a)

2CO(g) + O2 (g) <=======> 2CO2(g)

Partial pressure of O2 increased so Q will decrease

RTlnQ value further decreases that is

value further decreases

As delta G value gets negative favors forward reaction that means shift reaction from left to right

And favors the formation of CO₂.

b)

H2O2(l) <======> 2H2O(l) + O2(g)

Puer liquids and solids are not included in the equilibrium constant expression

Therefor, Q = [O2]

As O2 partial pressure was increased Q value will also increase

RTlnQ value get increase

Therefore, value increase

If delta G value increase Forward reaction decreases and backward reaction favors

So formation of H2O2 will increase

C)

2KClO3(s) <=====>2KCl(s) + 3O2(g)

Q = [O₂]³

As the partial pressure of O2 increase Q value increase exponentially

So RTlnQ value will also increase

Therefore, value will increase

If delta G value increase Forward reaction decreases and backward reaction favors

So formation of KClO₃ will increase