Question

So, I think I'm doing everything right and even checking my math, but it keeps showing up as wrong. If someone can help me and go into detail,including the quadratic formula, I would appreciate it:
Phosphorus pentachloride decomposes according to the chemical equation
Pcl5(g)=Pcl3+ Cl2
Kc=1.8 at 250 Celsius
a 0.204 mol sample of Pcl5 is injected into a 2.4 L reaction vessel held ate 250 degrees Celsius. Calculate the concentrations of PCl5 and PCl3 at equilibrium.

Answer 1

I shall be happy to check your work if you show it and post as a new question at the top of the page. It's easier for us to check your work than to do all of the work ourself and have you go through and try to find your error.

Answer 2

Kc=0.040