Two pieces of metal can be joined by welding them together - Edexcel - GCSE Chemistry - Question 1 - 2013 - Paper 1
Question 1
Two pieces of metal can be joined by welding them together.
(i) Complete the sentence by putting a cross (✗) in the box next to your answer.
The structure of a meta... show full transcript
Worked Solution & Example Answer:Two pieces of metal can be joined by welding them together - Edexcel - GCSE Chemistry - Question 1 - 2013 - Paper 1
Step 1
Complete the sentence by putting a cross (✗) in the box next to your answer.
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Answer
The structure of a metal is a lattice of C cations in a sea of electrons. This reflects the metallic bonding where positively charged cations are surrounded by delocalized electrons, allowing conductivity and malleability.
Step 2
State why a high temperature has to be used.
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Answer
A high temperature is necessary because metals have high melting points, which means a significant amount of energy is required to break the strong metallic bonds and allow the metals to melt for welding.
Step 3
Explain why an atmosphere of argon is used.
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Answer
An atmosphere of argon is used during welding because argon is an inert gas. It prevents oxidation or contamination of the molten metal by displacing oxygen and moisture from the environment, ensuring a cleaner weld.
Step 4
Write the balanced equation for this reaction.
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Answer
The balanced equation for the reaction of iron with bromine is:
ightarrow ext{2FeBr}_3$$
Step 5
Complete the sentence by putting a cross (✗) in the box next to your answer.
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Answer
At room temperature, iodine is a B brown liquid. This reflects iodine's physical state under standard conditions.
Step 6
Use the information in the table to explain the order of reactivity of the three halogens.
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Answer
In the table, chloride shows no displacement reactions with bromide or iodide ions, indicating that chlorine is the most reactive halogen. Bromine can displace iodide ions, showing it is more reactive than iodine, but less reactive than chlorine. Thus, the order of reactivity of the three halogens is chlorine > bromine > iodine.
