Right, I am aware that the SDMB is not a homework club, and I am asking for advice only with my technique and mathematics, because it’s the weekend, and I’ve no-one else to ask!

I’m on an assignment titled “Assignment:Kc & Kp” at the moment, and I can’t work out what I’m doing wrong with this question;

Basically, it’s about this reaction:

CO[sub]2(g)[/sub] + H[sub]2(g)[/sub] <==> COsub[/sub] + H[sub]2[/sub]Osub[/sub]

which has a value of Kc of 1.60

It says that 2.00moles of CO[sub]2[/sub] and H[sub]2[/sub] are mixed in a closed container at a constant temp. The question is; how much CO[sub]2[/sub] will remain at equilbrium?

ok, Kc = ([CO] x [H2O]) / ([CO2] x [H2])

where is the concentration of x

Since we are given no total volume, but know it remains constant, we can disregard because it would cancel out on the top and bottom of the formula.

Also, according to the initial equation, we can call the equilibrium concentrations (2.00 - x) for CO2 and H2, and x for CO and H20. We should then rearrange to a quadratic, which can be solved to give x. From this, we can find 2.00 - x, which is our answer.

The assignment sheet states that I should get an answer of .88mol for the amount of CO2, but no matter how many different ways I re-arrange the equation, I cannot get this.

Is there anyone out there who can help me? My maths is rather poor, and I think it must be an elementary mistake I’ve made!

Thankyou in advance,

Harry