This question is about the halogens - AQA - GCSE Chemistry Combined Science - Question 4 - 2018 - Paper 1
Question 4
This question is about the halogens.
0 4.1
Write the state symbol for chlorine at room temperature.
Cl₂ ( ____ )
{1 mark}
0 4.2
Figure 4 represents one molecul... show full transcript
Worked Solution & Example Answer:This question is about the halogens - AQA - GCSE Chemistry Combined Science - Question 4 - 2018 - Paper 1
Step 1
Write the state symbol for chlorine at room temperature.
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Answer
The state symbol for chlorine at room temperature is 'g', indicating that it is a gas.
Step 2
Complete the dot and cross diagram on Figure 4.
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Answer
In the dot and cross diagram for one molecule of fluorine (F₂), each fluorine atom should have 6 electrons in its outer shell. The diagram should show a shared pair of electrons between the two fluorine atoms, represented by dots and crosses.
Step 3
What is the total number of electrons in a fluorine molecule (F₂)?
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Answer
A fluorine molecule (F₂) contains a total of 18 electrons. Each fluorine atom has 9 electrons, so for two atoms: 9 + 9 = 18.
Step 4
Complete the balanced chemical equation for this reaction.
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Answer
The balanced chemical equation for the reaction of aluminium with bromine to produce aluminium bromide is: 2 Al + 3 Br₂ → 2 AlBr₃.
Step 5
Explain why chlorine is more reactive than bromine.
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Answer
Chlorine is more reactive than bromine because it is a smaller atom with fewer energy levels and a higher electronegativity. Consequently, chlorine has a greater effective nuclear charge, allowing it to attract electrons more easily than bromine. In this context, chlorine can gain an electron into its outer shell more readily than bromine can.
