Magnesium reacts with dilute hydrochloric acid to produce magnesium chloride and hydrogen gas - Edexcel - GCSE Chemistry - Question 5 - 2018 - Paper 1

The formula of a molecule of hydrogen is:

H₂

The appropriate hazard symbol indicating that a substance is an irritant is A.

Experiment Steps:

1. Measure a fixed length and mass of magnesium ribbon using a ruler and balance.
2. Add the magnesium ribbon to a conical flask.
3. Use a measuring cylinder to measure a set volume of hydrochloric acid of a specific concentration.
4. Pour the hydrochloric acid into the conical flask containing magnesium.
5. Immediately place the gas syringe on top to collect the hydrogen gas released during the reaction.
6. Start the stopwatch simultaneously to measure the time taken for hydrogen production.
7. Repeat the experiment with different concentrations of hydrochloric acid, keeping the mass and surface area of magnesium constant.
8. Observe and record the volume of hydrogen produced at fixed time intervals to determine the rate of reaction.

Results:

• With a higher concentration of acid, a larger volume of hydrogen is produced in a shorter time.
• The greater the concentration of the hydrochloric acid, the higher the rate of reaction, which results in more hydrogen being formed more quickly.