What does the term rate of reaction mean?
Identify a change in the reaction mixture that would make it possible to investigate the rate of this reaction.
For this reaction, the rate equation is $\text{rate} = k[\text{NO}]^2[\text{H}_2]$. Use the data together with the rate equation to calculate the rate constant $k$. State the units of $k$.
A further experiment is carried out at the same temperature. The starting concentration of $\text{H}_2\text{(g)}$ is $4.60 \times 10^{-3}\,\text{mol dm}^{-3}$. The starting rate of reaction is $2.31 \times 10^{-3}\,\text{mol dm}^{-3}\,\text{s}^{-1}$. Calculate the starting concentration of $\text{NO(g)}$.
State the reaction order with respect to NO(g) and with respect to H$_2$(g), together with the overall order of reaction.
The reaction is thought to occur in three stages: 1. $\text{2NO} \rightarrow \text{N}_2\text{O}_2$ 2. $\text{N}_2\text{O}_2 + \text{H}_2 \rightarrow \text{N}_2\text{O} + \text{H}_2\text{O}$ 3. $\text{N}_2\text{O} + \text{H}_2 \rightarrow \text{N}_2 + \text{H}_2\text{O}$ Deduce which of the three stages is the rate-determining step.
Explain your answer to (i).
A third experiment is carried out under different conditions. A small amount of H$_2$(g), with concentration $0.0200\,\text{mol dm}^{-3}$, is mixed with a large excess of NO(g). The concentration of H$_2$(g) is found to have a constant half-life of $2.00\,\text{s}$ under the conditions used. Define the term half-life.
Using the axes given, draw a graph showing how the concentration of H$_2$(g) changes during the first $6\,\text{s}$ under the conditions used.
NO(g) acts as a catalyst in the oxidation of atmospheric sulfur dioxide. Give two equations that show how NO(g) acts as a catalyst in this process.
Explain why NO(g) may be described as a catalyst in this reaction.
Describe, with the aid of an equation, one environmental effect of the oxidation of atmospheric sulfur dioxide.