This question is about metals and metal compounds - AQA - GCSE Chemistry - Question 2 - 2018 - Paper 1
Question 2
This question is about metals and metal compounds.
Iron pyrites is an ionic compound.
Figure 1 shows a structure for iron pyrites.
Determine the formula of iron p... show full transcript
Worked Solution & Example Answer:This question is about metals and metal compounds - AQA - GCSE Chemistry - Question 2 - 2018 - Paper 1
Step 1
Determine the formula of iron pyrites.
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Answer
The formula of iron pyrites is ( FeS_2 ). This indicates that there is one iron atom for every two sulfur atoms.
Step 2
Number of protons
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Answer
The number of protons in the atom of iron is 26.
Step 3
Number of neutrons
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Answer
The number of neutrons in the atom of iron is 30.
Step 4
Number of electrons
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The number of electrons in the atom of iron is 26.
Step 5
Give two differences between the properties of iron and sodium.
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Answer
Iron has a higher melting and boiling point compared to sodium.
Iron is denser and generally harder than sodium.
Step 6
Explain why carbon can be used to extract nickel from nickel oxide.
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Carbon can be used for the reduction of nickel oxide because it is more reactive than nickel. It displaces nickel from nickel oxide through a chemical reaction.
Step 7
Calculate the percentage atom economy for the reaction to produce nickel.
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The total relative formula mass of the reactants is ( 75 + 12 = 87 ).
The relative atomic mass of nickel produced is 59.
The percentage atom economy is calculated using the formula:
[ ext{Percentage Atom Economy} = \left( \frac{\text{mass of useful product}}{\text{total mass of reactants}} \right) \times 100 = \left( \frac{59}{87} \right) \times 100 \approx 67.8 % ]
Therefore, the atom economy is approximately 67.8%.
