The Mechanism for the Gas-Phase Reaction That Converts Nitrogen Dioxide

Multiple Choice

The mechanism for the gas-phase reaction that converts nitrogen dioxide, NO₂, into nitric oxide, NO, and oxygen, O₂ was explored by measuring the initial rate of the reaction for different pressures of reactant. The data below shows how the initial rate of reaction varied with the partial pressure of nitrogen dioxide at a temperature of 300 °C. An inert buffer gas was used so that the overall initial pressure was the same for each experiment. Use the method of initial rates to determine the order of the reaction.
$\begin{array}{lllll}\mathrm{p} / \mathrm{Pa} & 2000 & 4000 & 6000 & 8000 \\\mathrm{v}_{0} /\left(\mathrm{Pa} \mathrm{s}^{-1}\right) & 0.36 & 0.65 & 0.94 & 1.21\end{array}$

A) Zeroth order
B) First order
C) Second order
D) Third order