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A student investigated the effect of heat on four metal carbonates - Edexcel - GCSE Chemistry - Question 6 - 2013 - Paper 1
Question 6
A student investigated the effect of heat on four metal carbonates. Equal amounts of each carbonate were heated strongly, in the same way, in this apparatus. The ti... show full transcript
Worked Solution & Example Answer:A student investigated the effect of heat on four metal carbonates - Edexcel - GCSE Chemistry - Question 6 - 2013 - Paper 1
Step 1
Explain why it was important not to remove the heat from the test tube while the delivery tube was still in the limewater.
Answer
It is essential to keep the heat on the test tube while the delivery tube is in the limewater to ensure that any gas produced during the reaction can dissolve in the limewater. If the heat is removed too soon, the gas might not be fully absorbed, leading to inaccurate results. Additionally, the reaction that produces carbon dioxide could be influenced by temperature; hence, consistent heat helps to ensure that the gas continues to be generated.
Step 2
Suggest why the limewater did not turn milky when sodium carbonate was heated.
Answer
The limewater did not turn milky when sodium carbonate was heated because sodium carbonate does not decompose under the heating conditions applied in this experiment. Unlike other carbonates, it does not produce carbon dioxide, which is necessary to turn limewater milky.
Step 3
Step 4
Step 5
By describing uses of these three calcium compounds, explain why limestone is such an important raw material.
Answer
Limestone, primarily composed of calcium carbonate, is a crucial raw material for various applications:
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Building Material: Limestone is widely used in the construction industry for making concrete and cement, essential for constructing buildings, roads, and infrastructure.
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Manufacture of Calcium Oxide: When calcium carbonate is heated, it decomposes to produce calcium oxide (quicklime), which is utilized in the manufacture of glass, as well as in steelmaking and as a key ingredient in many industrial processes.
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Calcium Hydroxide Production: Calcium oxide can in turn be hydrated to produce calcium hydroxide (slaked lime), which is useful for treating water and improving soil conditioning in agriculture.
These compounds derived from limestone play vital roles in various industrial processes, making limestone an important and versatile raw material.