Chemistry

Problem

The gas-phase oxidation of nitric oxide is represented by the overall reaction

2\,\text{NO}(g) + \text{O}_2(g) \rightarrow 2\,\text{NO}_2(g)

Initial rate data were obtained at

323\,\text{K}

as shown in the table. One of the trials (marked with *) was suspected to be contaminated by an undetected leak in the apparatus.

Trial	[NO] $_0$ (M)	[O2] $_0$ (M)	Initial rate ( $\text{M}\,\text{s}^{-1}$ )
1	$0.010$	$0.010$	$3.0 \times 10^{-5}$
2	$0.020$	$0.010$	$1.2 \times 10^{-4}$
3	$0.040$	$0.010$	$4.7 \times 10^{-4}$
4	$0.010$	$0.020$	$5.9 \times 10^{-5}$
5*	$0.020$	$0.020$	$9.8 \times 10^{-5}$

(a) Using logarithms, determine the order of the reaction with respect to NO. Clearly indicate which trials you select and justify ignoring any trial you exclude from the analysis. (b) Using an analogous procedure, determine the order with respect to O2. (c) Write the complete rate law, calculate the numerical value of the rate constant

k

(to two significant figures) with appropriate units, and specify which trial you used for the calculation. (d) Explain how the units of

k

you reported in part (c) are consistent with the overall reaction order you determined.

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