Equilibrium constant

thepikminman

Hi,

I have this question:

H2(g) + CO2(g) --> H2O(g) + CO(g)

Lab measurements at 1000oC show that there are 0.12 mol of each of CO(g) and H2O(g), and 0.087 mole each of H2(g) and CO2(g) at equilibrium in a 1L container. Calculate the equilibrium constant for the reaction at 1000oC

*I just want to know what effect the 1000oC has on the equilibrium constant. And if the mole values given are the molar values, or if all the grams of the molecules make it less than a litre of water, so would you have to divide by whatever and find out how much there would be for one exact litre?*

My answer is 1.902

Thanks for your help if you decide to!!

SOL

An equilibrium constant is really just a measure of what, when a reaction gets to its stead state, the amount of product compared to starting material is going to be.

This is of course going to depend on temperature, but since you are only given one temperature, it doesn't really matter.


The equilibrium constant Kc is the the concentration of the products multiplied together / the starting materials multiplied together

Thus, if there is more product than starting material for a reaction that goes from two molecules to two other molecules we know that Kc is bigger than one and smaller than one if there is less.

A quick analysis of your example tells us that there is less product than starting material so Kc is smaller than one.

If we sub in the numbers we get 0.007569/0.0144 = 0.526

I have two questions for you,

1) Where did you get grams from your question?
2) Can you explain what you mean by make it less than a litre of water? (since all this is in the gas phase in a one litre container)


Feel free to correct me if I have gone wrong...

thepikminman

SOL wrote: »

An equilibrium constant is really just a measure of what, when a reaction gets to its stead state, the amount of product compared to starting material is going to be.

This is of course going to depend on temperature, but since you are only given one temperature, it doesn't really matter.


The equilibrium constant Kc is the the concentration of the products multiplied together / the starting materials multiplied together

Thus, if there is more product than starting material for a reaction that goes from two molecules to two other molecules we know that Kc is bigger than one and smaller than one if there is less.

A quick analysis of your example tells us that there is less product than starting material so Kc is smaller than one.

If we sub in the numbers we get 0.007569/0.0144 = 0.526

I have two questions for you,

1) Where did you get grams from your question?
2) Can you explain what you mean by make it less than a litre of water? (since all this is in the gas phase in a one litre container)


Feel free to correct me if I have gone wrong...

Thanks for your reply!

I got grams from finding out how many grams the molar values gave per litre and then found out how many grams per given mls. I don't know if that answers your question.

And I meant does it mean the weight of the substances + the weight of the water makes up 1 litre, or does it mean 1 litre of water + the substances.

How come it's in the gas phase, I thought it was in the liquid because I thought molar concentration was to do with liquids?

Thanks again!

SOL

Well, it's in the gas phase cause that is what your question says. The (g) after each component of the equation signifies that it is a gas. Concentration also applies to gasses, and (conceptually at least) to solids.

The reason I ask where you got grams is more because I was wondering why you got grams, the weight of each component doesn't matter, only the number of particles of it. (i.e. the number of moles which since all the components are in the same volume container will be proportionate to the concentration.)

Also, I'm not sure where water comes into the situation (except that there are 0.12 moles of it in the container), the question just means that it is a sealed container of internal volume 1 litre.