The rate law for the reaction `O_(3) + O rarr 2O_(2)` is rate `= k[O_(3)][NO]`. Then which is/are correct? (more than one correct)

Options

A. `NO` is catalyst.
B. `O` atom is not involved in slow step
C. The slow step is bimolecular.
D. None of these

Answer

To analyze the given reaction and the rate law, let's break down the information step by step.

### Step 1: Understand the Reaction and Rate Law
The reaction given is:
\[ O_3 + O \rightarrow 2 O_2 \]

The rate law provided is:
\[ \text{Rate} = k[O_3][NO] \]

Here, \( k \) is the rate constant, and the concentrations of \( O_3 \) and \( NO \) are involved in the rate expression.

**Hint:** Identify the components of the rate law and what they imply about the reaction mechanism.

### Step 2: Analyze the Role of NO
The first option states that NO is a catalyst. A catalyst is a substance that increases the rate of a reaction without being consumed in the process. Since NO appears in the rate law, it suggests that it plays a significant role in the reaction mechanism.

**Hint:** Recall the definition of a catalyst and how it appears in the rate law.

### Step 3: Determine the Involvement of Oxygen Atom
The second option claims that the oxygen atom (O) is not involved in the slow step. The rate law indicates that the rate of reaction depends on the concentrations of \( O_3 \) and \( NO \), but not on \( O \). This implies that \( O \) does not participate in the rate-determining step.

**Hint:** Consider what the rate law indicates about the reactants involved in the slow step.

### Step 4: Assess the Molecularity of the Slow Step
The third option states that the slow step is bimolecular. The rate law shows that the reaction rate depends on the concentrations of two species (\( O_3 \) and \( NO \)). This suggests that the slow step involves two reactants, making it bimolecular.

**Hint:** Recall the definitions of unimolecular, bimolecular, and termolecular reactions based on the number of reactants involved.

### Conclusion
Based on the analysis:
1. **NO is a catalyst** - Correct.
2. **Oxygen atom is not involved in the slow step** - Correct.
3. **Slow step is bimolecular** - Correct.

Thus, all three options are correct.

### Summary of Correct Options:
- Option 1: NO is a catalyst - **Correct**
- Option 2: Oxygen atom is not involved in the slow step - **Correct**
- Option 3: Slow step is bimolecular - **Correct**