# Chemistry, equilibrium molarity

posted by
**Taasha**
.

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.

This is what I've done so far: (.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, x is not 0.5. You aren't solving the equation Bob Pursley gave you correctly. Your first step should be to take the square root of both sides giving you

(0.5+x)/(0.5-x)= sqrt(3.75) and go from there.

I see what I did, it was a stupid math mistake