State the order of reaction with respect to $\text{CH}_3\text{COCH}_3$, $\text{I}_2$, and $\text{H}^+$, and state the overall order of this reaction.
The rate of this reaction is $5.40 \times 10^{-3}\,\text{mol dm}^{-3}\text{s}^{-1}$ when the concentration of $\text{CH}_3\text{COCH}_3$ is $1.50 \times 10^{-2}\,\text{mol dm}^{-3}$, the concentration of $\text{I}_2$ is $1.25 \times 10^{-2}\,\text{mol dm}^{-3}$, and the concentration of $\text{H}^+$ is $7.75 \times 10^{-1}\,\text{mol dm}^{-3}$. Calculate the rate constant, $k$, for this reaction. State the units of $k$.
Complete the table by placing one tick (✓) in each row to show the effect of decreasing the temperature on the rate constant and on the rate of reaction.
The rate of this reaction is $5.40 \times 10^{-3}\ \text{mol dm}^{-3}\ \text{s}^{-1}$ when: - the concentration of $\text{CH}_3\text{COCH}_3$ is $1.50 \times 10^{-2}\ \text{mol dm}^{-3}$ - the concentration of $\text{I}_2$ is $1.25 \times 10^{-2}\ \text{mol dm}^{-3}$ - the concentration of $\text{H}^+$ is $7.75 \times 10^{-1}\ \text{mol dm}^{-3}$
A graph from the results shows how the concentration of $\text{I}_2$ changes as the reaction proceeds. Describe how this graph could be used to determine the initial rate of the reaction.
On the axes below, sketch a graph to show how the initial rate varies with different initial concentrations of $\text{CH}_3\text{COCH}_3$ in this reaction.
The rate of a reaction between metal ions was investigated. A three-step mechanism has been proposed for this reaction, and Step 1 is the rate-determining step. Step 1: $\text{Ce}^{4+} + \text{Mn}^{2+} \rightarrow \text{Ce}^{3+} + \text{Mn}^{3+}$ Step 2: $\text{Ce}^{4+} + \text{Mn}^{3+} \rightarrow \text{Ce}^{3+} + \text{Mn}^{4+}$ Step 3: $\text{Mn}^{4+} + \text{Tl}^+ \rightarrow \text{Tl}^{3+} + \text{Mn}^{2+}$
Explain the meaning of the term rate-determining step.
Use this mechanism to: - determine the overall equation for this reaction - suggest the role of $\text{Mn}^{2+}$ ions in this mechanism. Explain your answer.