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
i) Which piece of apparatus should be used to find the mass of metal used?
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 correct piece of apparatus to find the mass of metal used is a balance. A balance accurately measures the mass of solids, which is essential for this experiment.
Step 2
ii) State two variables, apart from the mass of the metals, that should be controlled in this investigation.
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
Volume of acid should remain constant to ensure the same amount of HCl is used in each reaction.
Temperature should be controlled because varying temperatures can affect reaction rates.
Step 3
iii) Give the reason why copper does not produce any effervescence.
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
Copper does not produce any effervescence because it is less reactive than hydrogen, meaning it cannot displace hydrogen ions from the hydrochloric acid.
Step 4
iv) Fill in the missing state symbols in the equation.
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
In the reaction, the missing state symbols are:
Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)
Step 5
i) Write the formula of potassium sulfate.
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
The formula for potassium sulfate is K₂SO₄.
Step 6
ii) Calculate the mean mass of potassium sulfate obtained.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To calculate the mean mass of potassium sulfate obtained, add the masses from the experiments and divide by the number of experiments:
Mean mass = (5.22 g + 5.24 g + 5.21 g) / 3 = 5.22 g (to two decimal places).
