Which of the following statement is incorrect about order of reaction

Options

A. Order of reaction is determined experimentally
B. It is the sum of power of concentration terms in the rate law expression
C. It does not necessarily depend on stoichiometric coefficients.
D. Order of the reaction can not have fractional value.

Answer

To solve the question regarding which statement is incorrect about the order of a reaction, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding the Order of Reaction**:
- The order of a reaction is defined as the sum of the powers of the concentration terms in the rate law expression. It is determined experimentally and does not necessarily correlate with the stoichiometric coefficients of the reactants.

2. **Analyzing Each Statement**:
- **Statement A**: "The order of the reaction is determined experimentally."
- This statement is **correct**. The order of a reaction is indeed determined through experimental data.

- **Statement B**: "The order of the reaction is the sum of the power of concentration terms in the rate law expression."
- This statement is also **correct**. The order is calculated by summing the exponents of the concentration terms in the rate law.

- **Statement C**: "The order of the reaction does not necessarily depend on stoichiometric coefficients."
- This statement is **correct** as well. The order of a reaction can differ from the stoichiometric coefficients of the reactants.

- **Statement D**: "The order of the reaction cannot have fractional value."
- This statement is **incorrect**. The order of a reaction can indeed be fractional. For example, it can be 1/2, 2/3, etc., based on experimental results.

3. **Conclusion**:
- The incorrect statement among the options provided is **Statement D**: "The order of the reaction cannot have fractional value."

### Final Answer:
The incorrect statement about the order of reaction is: **"The order of the reaction cannot have fractional value."**

---