Which of the following is correct?

Options

A. Molecularity of a reaction can be fractional
B. Zero order reaction never stops
C. A first order reaction must be homogenous
D. The frequency of a Arrhenius type equation increases with increase in temperature

Explanation

To determine which of the statements is correct regarding chemical kinetics, we will analyze each option step by step.

### Step 1: Analyze the first statement
**Statement:** Molecularity of a reaction can be fractional.

**Explanation:** Molecularity refers to the number of reactant molecules involved in an elementary reaction. It is defined as an integer (1, 2, or 3) and cannot be fractional. Therefore, this statement is incorrect.

### Step 2: Analyze the second statement
**Statement:** Zero order reaction never stops.

**Explanation:** A zero-order reaction has a constant rate that does not depend on the concentration of the reactants. However, it does not mean that the reaction never stops; it will eventually stop when the reactants are consumed. Hence, this statement is also incorrect.

### Step 3: Analyze the third statement
**Statement:** A first-order reaction must be homogeneous.

**Explanation:** A first-order reaction can occur in different phases (heterogeneous) as well. For example, the decomposition of ammonium nitride is a first-order reaction that can involve solid and gaseous phases. Therefore, this statement is incorrect.

### Step 4: Analyze the fourth statement
**Statement:** The frequency of Arrhenius type reaction increases with increasing temperature.

**Explanation:** According to the Arrhenius equation, the rate constant (k) increases with an increase in temperature (T). As temperature rises, the kinetic energy of molecules increases, leading to more frequent and effective collisions. Thus, this statement is correct.

### Conclusion
Based on the analysis, the correct statement is:
- **The frequency of Arrhenius type reaction increases with increasing temperature.**