This question is about compounds of carbon - AQA - GCSE Chemistry - Question 2 - 2017 - Paper 1
Question 2
This question is about compounds of carbon.
Figure 2 shows an atom with two energy levels (shells).
(a)(i) A carbon atom has six electrons. Complete Figure 2 to sh... show full transcript
Worked Solution & Example Answer:This question is about compounds of carbon - AQA - GCSE Chemistry - Question 2 - 2017 - Paper 1
Step 1
Complete Figure 2 to show the electronic structure of a carbon atom
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Answer
The electronic structure of a carbon atom can be represented as follows:
The first energy level will contain 2 electrons and the second energy level will contain 4 electrons.
This can be illustrated as:
x
x •
Where '•' represents the nucleus.
Step 2
Complete the following description about the central part of this carbon atom
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Answer
The central part is made up of six neutrons that have no electrical charge and six protons which are positively charged.
Step 3
What does the term hydrocarbon mean?
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A hydrocarbon is made up of hydrogen and carbon (atoms) only.
Step 4
Complete the displayed structure of ethane and the displayed structure of ethene
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Answer
For ethane (C2H6), the displayed structure is:
H H
| |
H-C---C-H
| |
H H
For ethene (C2H4), the displayed structure is:
H H
| |
H-C===C-H
| |
H H
Step 5
Describe the relationship between the number of carbon atoms in an alkane molecule and the boiling point of the alkane molecule
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Answer
As the number of carbon atoms increases, the boiling point of the alkane molecule increases.
Step 6
Use the information in Table 2 to compare the boiling points of alkanes with the boiling points of alkenes
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The boiling points of alkanes are higher than the boiling points of alkenes that have the same number of carbon atoms. For example, hexane (C6H14) has a higher boiling point than hexene (C6H12).
Step 7
Describe what happens to the alkane molecules in this investigation
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When liquid paraffin (which contains alkanes) is heated to a high temperature, the alkane molecules undergo cracking, breaking down to produce smaller molecules, including other alkanes and alkenes. This process may involve decomposition or splitting into smaller components.
