This question is about the halogens - AQA - GCSE Chemistry Combined Science - Question 4 - 2018 - Paper 1
Question 4
This question is about the halogens.
04.1 Write the state symbol for chlorine at room temperature.
Cl₂ ( _____ )
04.2 Figure 4 represents one molecule of fluorine.... 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
04.1 Write the state symbol for chlorine at room temperature.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The state symbol for chlorine at room temperature is 'g' for gas.
Step 2
04.2 Complete the dot and cross diagram on Figure 4.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In the dot and cross diagram for fluorine (F₂), each circle should represent a fluorine atom with six outer shell electrons. Each atom should have three dots (✴) and three crosses (✪) to show the shared pair of electrons. Therefore, the diagram should have:
One fluorine atom with three crosses and three dots overlapping with the other fluorine's three crosses and three dots.
Step 3
04.3 What is the total number of electrons in a fluorine molecule (F₂)?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The total number of electrons in a fluorine molecule (F₂) is 18. Since each fluorine atom has 9 electrons, the combined total is 9 + 9 = 18.
Step 4
04.4 Complete the balanced chemical equation for this reaction.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The balanced chemical equation for the reaction is:
2 Al + 3 Br₂ → 2 AlBr₃.
Step 5
04.5 Explain why chlorine is more reactive than bromine.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Chlorine is more reactive than bromine because:
Chlorine is a smaller atom, so its outer electrons are closer to the nucleus, resulting in a stronger attractive force towards incoming electrons.
Chlorine has fewer energy levels compared to bromine, which means its outer shell experiences less shielding from inner electrons.
The greater attraction due to these factors allows chlorine to gain an electron more easily compared to bromine.
