CSEC Chemistry · May/June 2019 · Paper 2 · Question 1(a)(ii)

Michael and Jennifer investigated the effect of surface area on the rate of reaction between zinc metal (Zn) and dilute sulfuric acid (H₂SO₄). They used six different grades of granulated zinc, representing average radius sizes (in microns, µm). Six experiments were conducted using these zinc grades, reacting them with an excess of 0.5 mol dm⁻³ dilute sulfuric acid at 25 °C. The same mass (0.55 g) of zinc granules was used in all experiments. The time taken to collect 100 cm³ of hydrogen gas was recorded. Figure 1 shows stopwatch readings for Experiments 1-6, and Table 1 on page 6 provides some data.

Using the formula Rate = 1/Time, calculate the rate of reaction for each experiment and record these values to 3 decimal places in Column 4 of Table 1. The rate of reaction for Experiment 1 has already been calculated for you.

This question uses a figure or table from the paper — you'll see it when you practise.