chemical equilibrium. conceptual doubt

its given that

" Keq changes only when the temperature changes. There is no effect of change in pressure or concentrations on the value of Keq ."

Can someone please tell what is the reason behind this??????

6 Answers

24
eureka123 ·

it comes from Vant Hoff equation...if I rememeber correctly

1
shreya ·

yeah that k linked with t is fine.. but why does it doesnt change when pressure and concentrations are changed??

24
eureka123 ·

from formula its clear..both vant hoff and gibbs

but still a expalination(not so good)
when we change pressure,it may have an impact on equilibrium constant(instantaneously)..but we know that due to le Chatlier principle,reaction also shifts in a particular direction..thus keeping the eq constant same...

in fact it happens so fast that we are unable to recognise any change in K value

whereas when temp changes,significant changes in value of K is observed.

1
vector ·

@eureka yaar ,are u sure of ur explanation ?? i m not convinced[2]

24
eureka123 ·

hmm...that was just a try...

everything is clear from formula....but shreya wants to know some reason.. i am thinking abt it...came up with this....

1
shreya ·

nice try eureka123 but i wanted a better reason...

i just searched at wikipedia and they are saying that

"The pressure dependence of the equilibrium constant is usually weak in the range of pressures normally encountered in industry, and therefore, it is usually neglected in practice."
For different cases it does depends on the pressure but they describe these cases as "complicated matter".

Concentration Dependence has not been talked about at all...

Thanks for your try.

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