Define the equilibrium constants kc and kp as they relate to reactions involving gases. kc is the equilibrium constant in terms of the of the reactants and products involved in a reaction. kp is the equilibrium constant for reactions among in which the of the reactants and products is measured in terms of their . (b) how are kc and kp related mathematically? the equilibrium constants kc and kp are related by the following equation. kp = kc(rt)δn kc = (rt)δn kp kp = (rt)δn kc kc = kp(rt)δn in this equation, r is the ideal gas constant, t is the temperature in kelvin, and δn is the difference between the moles of gaseous products and the moles of gaseous reactants (products − reactants). the two constants will be when the number of moles on both sides of the reaction equation are equal. this is because δn will be 0, causing the term rt to equal 1.