Answered

### Question 2

Nitric oxide (NO) gas reacts with chlorine [tex]\([ \text{Cl}_2 ]\)[/tex] gas to produce NOCl. The reaction reaches equilibrium.

This is the balanced chemical equation for this reaction:
[tex]\[ 2 \text{NO} (g) + \text{Cl}_2 (g) \rightleftharpoons 2 \text{NOCl} (g) \][/tex]

Answer the following questions about this reaction. Use the provided data to answer questions about the reaction rate.

[tex]\[
\begin{tabular}{|c|c|c|}
\hline
\text{Initial [NO], M} & \text{Initial [Cl}_2\text{], M} & \text{Initial Reaction Rate} \\
\hline
0.2 & 0.3 & $2.2 \times 10^{-5}$ \\
\hline
0.2 & 0.6 & $4.4 \times 10^{-5}$ \\
\hline
0.4 & 0.3 & $8.8 \times 10^{-5}$ \\
\hline
\end{tabular}
\][/tex]

What is the order of the reaction with respect to [tex]\(\text{Cl}_2\)[/tex]?



Answer :

To determine the order of the reaction with respect to chlorine gas ([tex]\( Cl_2 \)[/tex]), we can use the data given and apply the method of initial rates.

From the given data table:

[tex]\[ \begin{array}{|c|c|c|} \hline \text{Initial [NO], M} & \text{Initial } \left[ Cl_2 \right]\text{, M} & \text{Initial Reaction Rate } [NOCl]/s \\ \hline 0.2 & 0.3 & 2.2 \times 10^{-5} \\ \hline 0.2 & 0.6 & 4.4 \times 10^{-5} \\ \hline 0.4 & 0.3 & 8.8 \times 10^{-5} \\ \hline \end{array} \][/tex]

We will compare the first two rows of the data where the concentration of [tex]\( \text{NO} \)[/tex] remains constant at 0.2 M. This allows us to isolate the effect of changing [tex]\( \left[ Cl_2 \right] \)[/tex] on the reaction rate.

1. Compare Trials 1 and 2:
- In Trial 1, the initial concentration of [tex]\( \left[ Cl_2 \right] \)[/tex] is 0.3 M and the initial rate is [tex]\( 2.2 \times 10^{-5} \, \text{s}^{-1} \)[/tex].
- In Trial 2, the initial concentration of [tex]\( \left[ Cl_2 \right] \)[/tex] is 0.6 M and the initial rate is [tex]\( 4.4 \times 10^{-5} \, \text{s}^{-1} \)[/tex].

2. Determine the ratio of the rates and concentrations:
- The ratio of the rates is:
[tex]\[ \frac{\text{Rate}_2}{\text{Rate}_1} = \frac{4.4 \times 10^{-5}}{2.2 \times 10^{-5}} = 2 \][/tex]
- The ratio of the concentrations of [tex]\( \text{Cl}_2 \)[/tex] is:
[tex]\[ \frac{\left[ Cl_2 \right]_2}{\left[ Cl_2 \right]_1} = \frac{0.6}{0.3} = 2 \][/tex]

3. Calculate the reaction order (n) with respect to [tex]\( \text{Cl}_2 \)[/tex]:
[tex]\[ \frac{\text{Rate}_2}{\text{Rate}_1} = \left( \frac{\left[ Cl_2 \right]_2}{\left[ Cl_2 \right]_1} \right)^n \][/tex]
[tex]\[ 2 = 2^n \][/tex]
By inspection, we can see that:
[tex]\[ n = 1 \][/tex]

Therefore, the order of the reaction with respect to [tex]\( \text{Cl}_2 \)[/tex] is 1.