What are the important features of equilibrium constant? Discuss any two applications of equilibrium constant.

Explanation

1. The equilibrium constant has a definite value of every chemical reaction at a particular temperature. The value of equilibrium constant is independent of initial concentration of reacting species.
2. The value of equilibrium constant K changes with change in temperature.
3. For a reversible reaction, the equilibrium constant for the backward reaction is inverse of the equilibrium constant for the forward reaction.
4. The equilibrium constant is independent of the presence of catalyst.
5. The equilibrium constant is expressed in terms of concentration, it has different units for different reactions.
6. When addition of two equilibria leads to another equilibrium then the product of their equilibrium constants gives the equilibrium constant of the resultant equilibrium.
eg: `N_(2)+O_(2)hArr2NO:K_(1)`
`2NO+O_(2)hArr2NO_(2),K_(2)`
`N_(2)+2O_(2)hArr2NO_(2),K_(3)`
`K=K_(1)xxK_(2)xxK_(3)`
Applications of equilibrium constant:
1. Predicting oif extent of reaction: the magnitude of equilibrium constant tells us about the extent to which the reactants are converted into the prodcts before the equilibrium is attained.
2. Predicting the direction of the reaction:
From the knowledge of equilibrium constant it is possible to predict the direction in which the net reaction is taking place at a given concentrations or partial pressures of reactants and products.
If `Q_(c)gtK_(c)` the reaction taking place in backward direction is more.
If `Q_(c)ltK_(c)` the reaction taking place in forward direction is more. If `Q_(c)=K_(c)` the reaction is at equilibrium.
No eaction taking place.