Photo AI
2 (a) Igneous, metamorphic and sedimentary are the three different types of rock - Edexcel - GCSE Chemistry - Question 2 - 2013 - Paper 1
Question 2
2 (a) Igneous, metamorphic and sedimentary are the three different types of rock. (i) Complete the sentence by putting a cross (✗) in the box next to your answer. ... show full transcript
Worked Solution & Example Answer:2 (a) Igneous, metamorphic and sedimentary are the three different types of rock - Edexcel - GCSE Chemistry - Question 2 - 2013 - Paper 1
Step 1
Step 2
Explain which of the three types of rock this is most likely to be.
Answer
The rock sample shown in the photograph is most likely to be sedimentary rock. This can be inferred because the sample contains fossils, which are typically found in sedimentary rocks. Metamorphic rocks do not usually contain fossils as the conditions for their formation destroy any organic material.
Step 3
Explain how these igneous rocks, containing different sized crystals, have been formed.
Answer
The two igneous rocks, A and B, have different crystal sizes due to their cooling processes. Rock A has small crystals, which indicates it cooled rapidly from magma at or near the Earth's surface (extrusive). In contrast, rock B has larger crystals because it cooled slowly from magma deep underground (intrusive), allowing more time for crystal growth.
Step 4
Explain why calcium carbonate is used to treat waste gases produced in coal-fired power stations.
Answer
Calcium carbonate is effective in treating waste gases because it reacts with acidic gases, like sulfur dioxide, to form a neutral compound. This reaction reduces the acidity of the gases, preventing environmental issues such as acid rain. The reaction can be summarized as follows:
ightarrow ext{CaSO}_3 + ext{CO}_2$$