A student used the apparatus in Figure 13 to investigate the rate of the reaction between a metal and dilute hydrochloric acid - Edexcel - GCSE Chemistry - Question 8 - 2022 - Paper 1

To calculate the mean rate of production of hydrogen, we first need to find the total volume of gas produced in the first 90 seconds from the graph in Figure 14. Let's denote this volume as V (cm³).

The formula for mean rate is:

$ext{Mean Rate} = \frac{\text{Total Volume}}{\text{Time}}$

In this case, Time = 90 seconds, so:

$\text{Mean Rate} = \frac{V}{90}$

Substituting the obtained value for V will provide the answer in cm³ per second.

The measurements could have been stopped at 9 minutes because the reaction would have reached completion, indicated by no further gas production, making it unnecessary to continue measuring.

Increasing the concentration of acid increases the number of acid particles in a given volume. This raises the likelihood of successful collisions between acid and metal particles, leading to more frequent reactions and hence a faster rate of reaction.

D use the same metal but in a powdered form.

The student can make small and medium sized marble chips by crushing the large chips using a pestle and mortar. After crushing, the student can then sieve the crushed material to separate smaller pieces according to size.