1. For an ideal gas, molarity is directly proportional to pressure M = P
therefore Kc is directly related to Kc by the equation:
Kp = Kc (RT)  n
where  n is the total number of product moles minus
the total number of reactant moles

2. Hydrogen and carbon dioxide gas react to form water vapor and carbon monoxide at high temperatures. At 420 C, the equilibrium constant, Kc is equal to What would be the equilibrium constant, Kp, if the concentration of the gases were measured in atm?
Kp = Kc (RT)  n
where  n is the total number of product moles minus the total
number of reactant moles
H2 + CO2  H2O + CO
 n = ( ) - ( ) = 0
Kp = Kc [( L atm/mol K)(693)] 0
Kp = Kc = 0.10
If the moles of products equals to moles of reactants, then
Kp = Kc

3. Hydrogen and nitrogen gases react to form ammonia
Hydrogen and nitrogen gases react to form ammonia. At 300 C, the equilibrium constant, Kc is equal to What would be the equilibrium constant, Kp, if the concentration of the gases were measured in atm?
Kp = Kc (RT)  n
where  n is the total number of product moles minus the total
number of reactant moles
3 H2 + N  2 NH3
 n = (2) - ( ) = -2
Kp = [( L atm/mol K)(573)] -2
Kp = x 10 -3