For the system CaO(s) + CO2(g) = CaCO3(s), I added 1.00 mol of CaO(s) to 1.00L of 0.500M CO2(g) at 200 oC. At equilibrium the [CO2] = 0.150M. What is the value of Kp for this reaction?

Question

For the system CaO(s) + CO2(g) = CaCO3(s),  I added 1.00 mol of CaO(s) to 1.00L of 0.500M CO2(g) at 200 oC.  At equilibrium the [CO2] = 0.150M.  What is the value of Kp for this reaction?

Kp would = CaCO3/(CaO)(CO2)

I do not know what to do with the 0.500M and 1.00mol.

DrBob222 · Answer

First you need to work on the Kp expression. SOLIDS aren't used (pure liquids aren't either) so the expression is 1/pCO2 = Kp.
The problem tells you that AT EQUILIBRIUM [CO2] = 0.150M.
I would calculate Kc from Kc = 1/([CO2]
then convert to Kp by Kp = Kc(RT)^Dn

Hannah · Answer

So I did 1/0.150 and got 6.66 so now I use this with RT. I am not sure what R is?

DrBob222 · Answer

R is 0.08206