Question

Which of the following is not a characteristic of equilibrium?
A.Rate is equal in both directions
B.Equilibrium occurs only in open vessels at constant temperature.
C.Measurable quantities are constant at equilibrium
D.Equilibrium occurs in reversible conditions.

Answer 1

Hint: We know that we can approach this question simply by the meaning of the word ‘Equilibrium’. Equilibrium is a state of rest or balance due to the equal action of opposing forces. It is an equal balance between something. We can connect this with a chemical reaction to arrive at the answer.

Complete answer:
Let us check now what ‘Chemical Equilibrium’ is. “Chemical equilibrium refers to the state of a system in which the concentration of the reactant and the concentration of the products do not change with time and the system does not display any further change in properties”. The state of chemical equilibrium is achieved by the system when the rate of forward reaction is equal to the rate of the reverse reaction.
The system is said to be in dynamic equilibrium when there is no further change in the concentrations of the reactants and the products due to the equal rates of the forward and backward reactions. Now we can go through the main characteristics of chemical equilibrium: -At equilibrium, the rate of forward reaction is equal to rate of backward reaction. All the reactants and products are present at chemical equilibrium.
There are some equilibrium concentrations in which the concentrations of the reactants and products reach constant values. A catalyst does not have the position of equilibrium. But it affects the rate at which the equilibrium attained.
Equilibrium state can only be achieved if a reversible reaction is carried out in a closed space.
Therefore, option (D) is the correct answer.

Note:
Remember that there are mainly two types of equilibrium. One is homogeneous equilibrium and another is heterogeneous equilibrium. In homogeneous equilibrium, the reactants and products are all in the same phase. While in heterogeneous equilibrium, the reactants and the products are in different phases.