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Calcium carbonate is an important raw material in the chemical industry - Edexcel - GCSE Chemistry - Question 6 - 2017 - Paper 1
Question 6
Calcium carbonate is an important raw material in the chemical industry. (a) Which of these is not made in a process using calcium carbonate? Put a cross (X) in th... show full transcript
Worked Solution & Example Answer:Calcium carbonate is an important raw material in the chemical industry - Edexcel - GCSE Chemistry - Question 6 - 2017 - Paper 1
Step 1
Step 2
In step A, a known mass of calcium carbonate is heated in order to obtain calcium oxide. The mass of the calcium oxide formed is found. Suggest how to continue the experiment to prove that the reaction is complete.
Answer
To prove the reaction is complete, heat the mixture for an extended time and then test for the absence of carbon dioxide gas using limewater. If no further change occurs in limewater, this indicates that no carbon dioxide is being released, confirming that the reaction is complete.
Step 3
Step 4
Explain how these rocks were formed.
Answer
The rocks are formed through various geological processes:
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Limestone: This is a sedimentary rock formed from the accumulation of marine organisms' shells and skeletons, primarily composed of calcium carbonate.
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Marble: This metamorphic rock is formed when limestone is subjected to high temperatures and pressures, causing recrystallization.
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Basalt: An igneous rock that forms from the rapid cooling of lava at the Earth’s surface, resulting in small crystals due to quick solidification.
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Granite: Another igneous rock that forms from the slow crystallization of magma beneath the Earth’s surface, leading to the formation of large crystals.