Question

How does concentration effect Le Chatelier's principle?

Answer 1

• According to Le Chatelier's principle, a disturbance in a system will cause a shift to counter the effect of this disturbance

Changes in concentration of reactants or products will cause a shift to reestablish the equilibrium.

• If the concentration of a substance is increased, the reaction shifts to consume the excess substance.

Conversely, if the concentration of a substance is decreased the reaction produces more of that substance until equilibrium is reestablished.

• Let us use the classic Haber reaction as an example

Nitrogen and hydrogen gases are reacted to produce ammonia

`N_2` + `3H_2` ----> 2 `NH_3`

If the concentration of nitrogen or hydrogen gas is increased, will cause both reactants to be consumed and thus shift the reaction to favor the product which is an increased concentration of ammonia.

• Similarly, you can also raise the concentration of ammonia by removing ammonia from the reaction mixture and thus shifting toward the product side.