A student investigated the rate of reaction between calcium carbonate chips and excess dilute nitric acid by monitoring the loss in mass as carbon dioxide gas escaped.
The table below shows the results of the investigation:
Time (s)Decrease in mass of reaction mixture (g)00.00300.48600.90901.221201.441501.601801.702101.752401.75\begin{array}{|c|c|} \hline \text{Time (s)} & \text{Decrease in mass of reaction mixture (g)} \\ \hline 0 & 0.00 \\ 30 & 0.48 \\ 60 & 0.90 \\ 90 & 1.22 \\ 120 & 1.44 \\ 150 & 1.60 \\ 180 & 1.70 \\ 210 & 1.75 \\ 240 & 1.75 \\ \hline \end{array}Time (s)0306090120150180210240Decrease in mass of reaction mixture (g)0.000.480.901.221.441.601.701.751.75Calculate the mean rate of reaction between 0 seconds0\text{ seconds}0 seconds and 120 seconds120\text{ seconds}120 seconds.
Use the equation:
mean rate of reaction=decrease in masstime taken \text{mean rate of reaction} = \frac{\text{decrease in mass}}{\text{time taken}} mean rate of reaction=time takendecrease in massState the value and choose the correct unit from: g/s\text{g/s}g/s, s/g\text{s/g}s/g, cm3/s\text{cm}^3\text{/s}cm3/s, or s/cm3\text{s/cm}^3s/cm3.
26 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1 Calculating rates of reactions, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.