1. If we reverse an equation KP or KC is reversed.If A + B ⇔ C + D KC = 10
then for C + D ⇔ A + B KC = 10-1
- ½ N2 + ½O2 ⇔ NO KC = 5
3. If we divide each of the coefficients in a balanced equation by a factor n, then new equilibrium constant is the nth root of the previous value.
2SO2 + O2 ⇔ 2SO3 KC =25SO2 + 1/2 O2 ⇔ SO3B KC = (25)1/2
4. When we combine individual equation, we have to multiply their equilibrium constant for net reaction.
If K1 , K2 and K3 are stepwise equilibrium constant for A⇔B , B⇔C , C⇔D .
Then for A⇔D , the equilibrium constant is K= K1K2K3
Significance of the magnitude of equilibrium constant:
- If a large value of KP or KC signifies that the forward reaction goes to completion or very nearly so.
- A large value of KP or KC signifies that the forward reaction doesn't occur to any significant extent.
- A reaction is most likely to reach a state of equilibrium in which both reactant and product are present if the numerical value of KP or KC is neither very large nor very small
Units of the equilibrium constant:
For the sake of simplicity in the units of Kc or Kp the relative molarity of pressure of reactants and products are used with respect to standard condition. (For solution standard state 1 mol/liter and for gas standard pressure=1 atm).Now resulting equilibrium constant becomes unitless by using relative molarity and pressure. But the numerical value may change in the value of standard states molarity and pressure.