Question

What does Le Chatelier’s Principle State?
A) That any change in a substance on one side of the equation, either in concentration, temperature, pressure or volume, results in an equilibrium shift to oppose the change until a new equilibrium is reached.
B) That the forward rate of the reaction is equal to the reverse rate of the reaction.
C) That the equilibrium is always achieved in any reaction.
D) That any change in a substance on one side of the equation results in an equilibrium shift to increase the change until a new equilibrium is reached.

Answer 1

Hint: First we should know in which field the Le Chatelier worked. Once we know about him then we could state the principle. To make better understanding we should also provide an example.

Complete step by step solution:
Le Chatelier was an engineer but then he chose to reach chemistry.
The Le Chatelier’s Principle states that any change in a substance on one side of the equation, either in concentration, temperature, pressure or volume, results in an equilibrium shift to oppose the change until a new equilibrium is reached.
Example: When concentration of reactant is increased, the equilibrium shifts in the forward direction. Since, more reactants will react, it will decrease the reactant concentration.
Example: We can look up to hydrogen iodide dissociation reaction.
$2HI \to {H_2} + {I_2}$, Now if we add more hydrogen into the container. The concentration of Hydrogen is more than the equilibrium value, so the equilibrium is disturbed. Now according to Le Chatelier principle the reaction will move in a direction to minimize the effects of excess ${H_2}$ This will occur in more hydrogen reacted by Iodine which will take reaction in reverse direction. In simple words we can say that equilibrium shifts to the left.

Hence, the correct answer is option A.

Note: Le Chatelier was a French Chemist who gave the principle which is used to predict the change in conditions of a chemical reaction. He gave the principle in 1884. His saying was that a system always acts to oppose changes in the equilibrium, it will always try to eliminate the disturbance.