Consider the reversible reaction of carbon monoxide and water vapor yielding car
ID: 827628 • Letter: C
Question
Consider the reversible reaction of carbon monoxide and water vapor yielding carbon dioxide and hydrogen. We have 1 mole each of the starting reactants in a 50 L reaction vessel. The equilibrium constant K is 0.58 at 1000 C. How many moles of each substance are in the equilibrium mixture? Also, calculate Kp for this reaction.
I already have the moles of each substance in the equilibrium mixture. I'm having trouble figuring out the Kp for this reaction.
This is what I got so far, but I'm not sure if it is raised to the 0 power or 2nd power in order to find delta n.
Kp = 0.58[(0.082 L*atm/K*mol)(1273 K)]^0 = 60.62
or
Kp = 0.58[(0.082 L*atm/K*mol)(1273 K)]^2 = 3.67x10^3
Thank you in advance for any help!
Explanation / Answer
molar concentration = number of moles/volume in litre
CO(g) + H2O(g) <====> CO2(g) + H2(g)
initially (1/50)M (1/50)M 0 0
at equilibrium (0.02-x) (0.02-x) x x
therefore, Kc = x^2/(0.02-x)^2
or, 0.58 = x^2/(0.02-x)^2
or, x= 0.00865M
therefore moles of CO2 at equilibrium = 50x = 0.4325
moles of H2 at equilibrium = 50x = 0.4325
moles of CO at equilibrium = 50*(0.02-x) = 0.5675
moles of H2O at equilibrium = 50*(0.02-x) = 0.5675
now, Kp = Kc*(RT)^n ; where n= number of moles of gaseous products - number of moles of gaseous reactants in the balanced equation
in this reaction n= 0
therefore Kp =Kc= 0.58