In a reversible reaction, the equilibrium constant Kc changes only when there is a change in
- A. concentration of the reactants
- B. pressure of the system
- C. temperature
- D. the catalyst used
Explanation
Concentration and pressure changes shift the position of equilibrium so that the same value of Kc is restored, and a catalyst affects only the rate, so none of them alters the constant. Temperature is different because it changes the relative rates of the forward and reverse reactions unequally, giving a genuinely new value of Kc. For an exothermic reaction Kc falls as the temperature rises.