Posted by **Taasha** on Monday, July 30, 2007 at 7:04pm.

At a particular temperature, K=3.75 for the following reaction. SO2(g) + NO2(g) (reversible arrows) SO3(g) + NO(g) If all four gases had initial concentrations of 0.500 M, calculate the equilibrium concentrations of the gases.

K=(.5+x)^2/(.5-x^2)

solve for x

I will be happy to critique your thinking

I might have done something wrong. I get that SO2 and NO2 have concentrations of 0 and SO3 and NO have concentrations of 1. That doesn't seem correct, but I did the work several times.

Post your work and we will find your error.

Thanks! (.5+x)2/(.5-x)2=3.75 When I solved for x, I got x=.5. When plugging into the original concentrations, you get that at equilibrium, since SO2 and NO2 are both initially .500 M, that they are 0 M. SO3 and NO are initially .500 M so at equilibrium they are 1 M. Correct?

No. Show your work. You should have

(0.5+x)(0.5-x) = sqrt (3.75)

and solving that equation doesn't give 0.