The reactivity of copper, magnesium and zinc was investigated - Edexcel - GCSE Chemistry Combined Science - Question 3 - 2019 - Paper 1
Question 3
The reactivity of copper, magnesium and zinc was investigated.
Each metal was placed separately in dilute hydrochloric acid.
The amount of effervescence was observed... show full transcript
Worked Solution & Example Answer:The reactivity of copper, magnesium and zinc was investigated - Edexcel - GCSE Chemistry Combined Science - Question 3 - 2019 - Paper 1
Step 1
Which piece of apparatus should be used to find the mass of metal used?
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Answer
The appropriate piece of apparatus to find the mass of metal used is A balance. A balance accurately measures the mass of materials, ensuring that the same amount of metal is utilized in each experiment.
Step 2
State two variables, apart from the mass of the metals, that should be controlled in this investigation.
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Answer
Same volume of acid used in each experiment.
Same concentration of acid.
Step 3
Give the reason why copper does not produce any effervescence.
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Answer
Copper does not produce any effervescence because it is less reactive than hydrogen. In dilute hydrochloric acid, hydrogen ions are reduced to form hydrogen gas, but since copper cannot displace hydrogen from this solution, no reaction occurs.
Step 4
Fill in the missing state symbols in the spaces provided.
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Answer
The balanced equation for the reaction is:
Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)
Step 5
Write the formula of potassium sulfate.
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Answer
The formula of potassium sulfate is K₂SO₄.
Step 6
Calculate the mean mass of potassium sulfate obtained, giving your answer to two decimal places.
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Answer
To find the mean mass of potassium sulfate, sum the masses from the three experiments and divide by the number of experiments:
Mean mass = ( rac{5.22 + 5.24 + 5.21}{3})
Mean mass = ( rac{15.67}{3} = 5.22 g)
Therefore, the mean mass of potassium sulfate obtained is 5.22 g.
