Which of the following statements is/are correct.:

Options

A. At equilibrium, vapour pressure of solution and refractive index of eq. mixture becomes constant.
B. Equilibrium can be attained in both homogenous and heterogenous reaction.
C. Approach to the equilibrium is fast in initial state but gradually it decreases.
D. Equilibrium is dynamic in nature

Answer

To determine which statements are correct regarding chemical equilibrium, we will analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement:** At equilibrium, vapor pressure and refractive index of the equilibrium mixture become constant.

**Explanation:** At equilibrium, the rates of the forward and backward reactions are equal, leading to no net change in the concentrations of reactants and products. This constancy extends to physical properties such as vapor pressure and refractive index, which also stabilize at a certain value.

**Conclusion:** This statement is correct.

### Step 2: Analyze the second statement
**Statement:** Equilibrium can be attained in both homogeneous and heterogeneous reactions.

**Explanation:** Homogeneous reactions involve reactants and products in the same phase (e.g., all gases or all liquids), while heterogeneous reactions involve different phases (e.g., solid and gas). Both types of reactions can reach equilibrium, where the rates of the forward and reverse reactions become equal.

**Conclusion:** This statement is correct.

### Step 3: Analyze the third statement
**Statement:** The approach to equilibrium is fast in the initial state but gradually decreases.

**Explanation:** Initially, when reactants are present in high concentrations, the rate of the forward reaction is high, leading to a rapid approach to equilibrium. As the reaction proceeds and reactant concentrations decrease, the rate of reaction slows down, resulting in a gradual decrease in the speed of approaching equilibrium.

**Conclusion:** This statement is correct.

### Step 4: Analyze the fourth statement
**Statement:** Equilibrium is dynamic in nature.

**Explanation:** At equilibrium, the forward and reverse reactions continue to occur, but their rates are equal, resulting in no net change in concentrations. This means that while the system appears static, it is actually dynamic, with continuous molecular activity.

**Conclusion:** This statement is correct.

### Final Conclusion
After analyzing all four statements, we conclude that all of them are correct.