The rate constant for a reaction is determined at different temperatures. Which diagram represents the relationship between the rate constant, $k$ , and temperature, $T$ , in K ?

C

This question could be answered if students knew that the relationship between $k$ and $T$ is exponential (as stated in A.S. 16.3.1), but it was not necessary that students recalled the Arrhenius equation. Candidates found the question difficult, having only 46% correct answers.