[molemole]

I am a little confused with this. N2(g) + 3H2(g) <--> 2NH3(g). It is an endothermic reaction of +92KJ. If you add more heat will the [NH3] lower, partial pressure of ammonia increase, partial pressure of hydrogen increase, or Kc decrease?

[0rion]

Hi Molemole,

This is obviously a multi-choice q so ill go through them one by one for you XD

By adding more heat...

a) [NH3] would increase, as the reaction is endothermic, and an energy input would drive it in the forward direction. So this one is wrong.

b) If the [NH3] increases (which it does as i have just mentioned) then the pressure exerted by NH3 (or partial pressure of NH3) must also increase, therefore this is the correct answer.

c) By driving the forward reaction, the concentration of [H] is going to decrease, and therefore so will its partial pressure.

d) Kc is defined as products/reactants. So by driving the reaction forward, you will increase the numerator, and this will increase Kc, so this one is wrong as well.

Hope my explanations have helped

[molemole]

Thanks for the help. The partial pressures are what threw me off.