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The apparatus shown was used by a student to investigate the reaction between strips of magnesium ribbon and excess dilute hydrochloric acid - Edexcel - GCSE Chemistry - Question 4 - 2015 - Paper 1
Question 4
The apparatus shown was used by a student to investigate the reaction between strips of magnesium ribbon and excess dilute hydrochloric acid. The word equation for ... show full transcript
Worked Solution & Example Answer:The apparatus shown was used by a student to investigate the reaction between strips of magnesium ribbon and excess dilute hydrochloric acid - Edexcel - GCSE Chemistry - Question 4 - 2015 - Paper 1
Step 1
Explain the difference between magnesium chloride(aq) and magnesium chloride(l).
Answer
Magnesium chloride (aq) indicates that the magnesium chloride is in aqueous solution, meaning it is dissolved in water. On the other hand, magnesium chloride (l) indicates that it is in the liquid state, typically referring to the pure liquid form of magnesium chloride, which may not necessarily mean it is in solution.
Step 2
Describe what you would see when magnesium ribbon reacts with dilute hydrochloric acid.
Answer
When magnesium ribbon reacts with dilute hydrochloric acid, you would observe effervescence or bubbling, indicating the release of hydrogen gas. Additionally, the magnesium ribbon will gradually disappear, and the solution may become warmer due to the exothermic nature of the reaction.
Step 3
Step 4
Step 5
On the graph draw a curve to show how the volume of hydrogen changes with time during this experiment.
Answer
The graph will depict a curve that starts steep and gradually levels off, indicating that the volume of hydrogen produced increases rapidly initially and then slows down as the reaction approaches completion.
Step 6
Explain the effect on the rate of reaction of using magnesium powder instead of magnesium ribbon.
Answer
Using magnesium powder instead of ribbon increases the rate of reaction due to the increased surface area of magnesium powder. This allows more collisions between magnesium and hydrochloric acid molecules, leading to a faster rate of hydrogen gas production.
Step 7
Explain what conclusion can be made about the type of reaction, from these results.
Answer
The increase in temperature from 21°C to 62°C indicates that the reaction between magnesium and hydrochloric acid is exothermic, meaning it releases heat. This suggests that the chemical reaction is likely to be a neutralization reaction between an acid and a reactive metal.