Question

The equilibrium constant of a reaction depends on:

• A. Pressure only
• B. Temperature only
• C. Concentration of reactants
• D. Initial composition

Hint:

Logic Tip: Le Chatelier's principle shifts the chemical balance around to compensate for pressure or concentration changes, but changing the Temperature is the only thing that permanently changes the mathematical rules of the balance itself (the Constant)!

Answer 1

The Correct Option is B

Concept:
The thermodynamic equilibrium constant ($K_{eq}$) dictates the ratio of product concentrations to reactant concentrations when a reversible chemical reaction reaches a state of balance.

Step 1: The equilibrium constant is fundamentally linked to the standard Gibbs free energy change of the reaction via the equation: $\Delta G^\circ = -RT \ln(K_{eq})$.

Step 2: In this equation, '$R$' is the universal gas constant, and $\Delta G^\circ$ is a fixed value for a specific reaction under standard conditions. The only operating variable that remains is Temperature ($T$).

Step 3: While changing the concentration, pressure, or volume will shift the position of the equilibrium left or right (Le Chatelier's principle), the actual numerical value of the equilibrium constant $K_{eq}$ itself remains unchanged.

Step 4: Therefore, for a specific given chemical reaction, the equilibrium constant is a function of temperature and temperature alone.