Yes, there is a relationship between Kp and Kc for an irreversible reaction. Kp and Kc represent equilibrium constants for a chemical reaction, but they are expressed in different ways depending on whether the reaction is in terms of partial pressures (Kp) or molar concentrations (Kc).
For an irreversible reaction, the equilibrium constant is not applicable since the reaction proceeds in one direction only and does not reach equilibrium. However, if the reaction is written in the same form as the equilibrium expression, the ratio of the partial pressures or molar concentrations at any point during the reaction can still be calculated.
If the reaction is reversible and can reach equilibrium, the relationship between Kp and Kc is determined by the ideal gas law and the expression of the reaction. For a reaction in the gas phase, the relationship is as follows:
Kp = Kc(RT)^(Δn)
Where: Kp is the equilibrium constant expressed in terms of partial pressures. Kc is the equilibrium constant expressed in terms of molar concentrations. R is the ideal gas constant. T is the temperature in Kelvin. Δn is the difference in the total number of moles of gaseous products and reactants.
The Δn term takes into account the stoichiometry of the reaction and the changes in the number of moles of gas between the reactants and products. It adjusts the relationship between Kp and Kc based on the gas laws.
It's important to note that this relationship applies only to reversible reactions, as irreversible reactions do not have an equilibrium constant in the same sense.