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2. (a) Zinc is a metal - Edexcel - GCSE Chemistry - Question 2 - 2013 - Paper 1
Question 2
2. (a) Zinc is a metal. Zinc reacts with dilute hydrochloric acid to produce zinc chloride and hydrogen. Edward used this apparatus to investigate the speed of the... show full transcript
Worked Solution & Example Answer:2. (a) Zinc is a metal - Edexcel - GCSE Chemistry - Question 2 - 2013 - Paper 1
Step 1
Sketch a line on the graph to show the results that Edward should expect to obtain if he carried out the experiment to completion at 30 °C.
Answer
To sketch a line representing the expected results at 30 °C:
- Start the line at the origin, indicating the beginning of the reaction.
- Ensure the line has a lower gradient than the line for 50 °C, reflecting a slower reaction rate at the lower temperature.
- Level off the line at the same volume of gas as the 50 °C curve, indicating that the reaction will eventually reach a similar endpoint in volume, despite the slower rate.
Step 2
Explain why zinc powder reacts faster than zinc pieces.
Answer
Zinc powder reacts faster than zinc pieces due to its larger surface area. A greater surface area allows more particles to be in contact with the acid, leading to more frequent collisions between zinc and hydrochloric acid molecules. Therefore, the reaction occurs more quickly as there are more successful collisions, increasing the rate of reaction.
Step 3
Explain the role of energy in breaking and forming bonds.
Answer
Breaking bonds requires energy, as this process is endothermic. Conversely, forming bonds releases energy, making it exothermic. When a reaction occurs, more energy is usually given out than is taken in, which results in a net release of energy during the reaction, thus influencing the overall energy dynamics.