Calcium carbonate reacts with dilute hydrochloric acid to produce carbon dioxide gas - Edexcel - GCSE Chemistry - Question 9 - 2020 - Paper 1

To find the average rate of reaction, we use the formula:

$ext{Average Rate} = \frac{\text{Volume of gas produced}}{\text{Time}}$

Here, the volume produced is 90 cm³ over a time period of 5 minutes, which is equivalent to 300 seconds:

$\text{Average Rate} = \frac{90 \text{ cm}^3}{300 \text{ s}} = 0.3 \text{ cm}^3/s$

When the temperature increases, particles gain more energy, causing them to move faster. This results in:

1. More frequent collisions between reactant particles, enhancing the chances of reaction.
2. Higher proportion of collisions that have enough energy to overcome the activation energy barrier, increasing the rate of product formation.