Which of the following features is NOT a characteristic of a state of equilibrium? A - HSC - SSCE Chemistry - Question 3 - 2022 - Paper 1

To determine which of the listed options is NOT a characteristic of a state of equilibrium, we will evaluate each one:

1. Equilibrium is achieved in a closed system.
   This statement is true. Equilibrium occurs in a closed system where no matter is exchanged with the surroundings.

2. Equilibrium position depends on temperature.
   This statement is also true. The position of equilibrium can shift with changes in temperature, particularly in exothermic and endothermic reactions.

3. Equilibrium can be reached from either direction.
   This statement is true as well, since a reaction can proceed to reach equilibrium from either reactants or products.

4. Equilibrium concentrations of reactants and products are equal.
   This statement is NOT true. At equilibrium, the concentrations of reactants and products may not be equal; they are constant but can vary depending on the reaction.

Based on the evaluations, the answer is D.