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Equilibrium and rate question Alevel Chemistry

suggest which set of changes would definitely produce an overall increase in both rate and yield for the following reaction. Explain your choice

N2 (g) + O2 (g) ⇌ 2NO(g)

A) Increasing pressure and increasing the temp
B) using a suitable catalyst and decreasing the temp
C) using a suitable catalyst and decreasing the pressure
D) decreasing the temp and decreasing the pressure

At first I thought it was C because the catalyst would speed up the rates but because the moles are equal pressure would have no effect on the yield? I think?
Any help would help! 😅😊
Thank you

Reply 1

JaffaCakeBiscuit

Is the forward reaction endo or exothermic?
You are correct - pressure has no effect on the rate of reaction in this case. A catalyst would speed up the rate but has no effect of the position of equilibrium. So it seems like the answer would be B, but only if the forward reaction is exothermic.

Reply 2

NKISS

Sorry for not mentioning the reaction is endothermic

(edited 3 years ago)

Reply 3

NKISS

Original post by JaffaCakeBiscuit

The reaction is endothermic.

Reply 4

CeyJai

Pressure will have no affect on yield, as there is equal amounts of mols of gas on either side but will have an effect on rate of reaction. If the reaction is endothermic (positive enthalpy change) then increasing temp will increase yield while also providing a faster rate of reaction. If the reaction is exothermic (negative enthalpy change) then an decrease im temp will increase yield, however will decrease rate of reaction.Therefore if the reaction is endothermic, choose AIf it is exothermic choose B.

(edited 3 years ago)

Reply 5

NKISS

Original post by CeyJai

Pressure will have no affect on yield, as there is equal amounts of mols on either side but will have an effect on rate of reaction. If the reaction is endothermic (positive enthalpy change) then increasing temp will increase yield while also providing a faster rate of reaction. If the reaction is exothermic (negative enthalpy change) then an decrease im temp will increase yield, however will decrease rate of reaction.Therefore if the reaction is endothermic, choose AIf it is exothermic choose B.