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A student investigated the rate of reaction between dilute hydrochloric acid and marble chips (calcium carbonate) - Edexcel - GCSE Chemistry - Question 8 - 2016 - Paper 1
Question 8
A student investigated the rate of reaction between dilute hydrochloric acid and marble chips (calcium carbonate). Calcium chloride, carbon dioxide and water are fo... show full transcript
Worked Solution & Example Answer:A student investigated the rate of reaction between dilute hydrochloric acid and marble chips (calcium carbonate) - Edexcel - GCSE Chemistry - Question 8 - 2016 - Paper 1
Step 1
Complete and balance the equation for the reaction.
Answer
The balanced chemical equation for the reaction between calcium carbonate (CaCO₃) and hydrochloric acid (HCl) is given as:
Here, one mole of calcium carbonate reacts with two moles of hydrochloric acid to produce one mole of calcium chloride, one mole of carbon dioxide, and one mole of water.
Step 2
State how the graph shows that line B gives the results for the larger marble chips.
Answer
Line B on the graph shows a steeper slope compared to line A, indicating a faster rate of reaction.
This suggests that the larger marble chips present a greater surface area for the reaction with hydrochloric acid, resulting in an increased rate of gas production over time.
Step 3
A tangent has been drawn on line A.
Answer
The tangent drawn on line A represents the instantaneous rate of reaction at a specific time in the experiment. It illustrates how the rate of gas production changes as time progresses, allowing for the calculation of the reaction rate at that exact moment based on the gradient of the tangent.