For the reaction `NO_(2)+COrarrCO_(2)+NO`, the experimental rate expresison is `-dc//dt = k[NO_(2)]^(2)`. Find the number of molecules of `CO` involved in the slowest step.

Answer

To solve the problem, we need to analyze the given reaction and the rate expression provided. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Reaction
The reaction given is:
\[ \text{NO}_2 + \text{CO} \rightarrow \text{CO}_2 + \text{NO} \]

### Step 2: Identify the Rate Expression
The experimental rate expression provided is:
\[ -\frac{d[\text{C}]}{dt} = k[\text{NO}_2]^2 \]
This indicates that the rate of the reaction depends on the concentration of \(\text{NO}_2\) raised to the power of 2.

### Step 3: Determine the Rate-Determining Step
In chemical kinetics, the rate-determining step (RDS) is the slowest step in a reaction mechanism that dictates the overall rate of the reaction. Since the rate expression is dependent only on \([\text{NO}_2]\), this suggests that the slowest step involves \(\text{NO}_2\) and does not involve \(\text{CO}\).

### Step 4: Analyze the Involvement of CO
The question asks for the number of molecules of \(\text{CO}\) involved in the slowest step. Since the rate expression does not include \([\text{CO}]\), it implies that \(\text{CO}\) does not participate in the rate-determining step.

### Step 5: Conclude the Number of CO Molecules
Since \(\text{CO}\) is not involved in the slowest step, the number of molecules of \(\text{CO}\) in the slowest step is:
\[ \text{Number of CO molecules} = 0 \]

### Final Answer
The number of molecules of \(\text{CO}\) involved in the slowest step is **0**.

---