This question is about zinc and compounds of zinc - AQA - GCSE Chemistry - Question 4 - 2022 - Paper 1
Question 4
This question is about zinc and compounds of zinc.
A student produces pure crystals of zinc chloride by reacting zinc oxide with hydrochloric acid.
The equation fo... show full transcript
Worked Solution & Example Answer:This question is about zinc and compounds of zinc - AQA - GCSE Chemistry - Question 4 - 2022 - Paper 1
Step 1
Give one observation that the student could make to show that the zinc oxide is in excess.
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 student could observe that unreacted zinc oxide remains as a solid, indicating it is in excess and does not dissolve.
Step 2
Why is excess zinc oxide used rather than excess hydrochloric acid?
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
Excess zinc oxide can be filtered off easily once the reaction is complete, making the process simpler compared to using excess hydrochloric acid.
Step 3
Name one other compound that the student could add to hydrochloric acid to produce zinc chloride.
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 student could add zinc hydroxide (Zn(OH)₂) or zinc carbonate (ZnCO₃) to hydrochloric acid to produce zinc chloride.
Step 4
Describe how the student should obtain crystals of zinc chloride from a solution of zinc chloride.
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 student should heat the solution until the crystallisation point is reached, allowing crystals to form. This can be accomplished by evaporating some water, and then allowing the solution to cool or crystallise.
Step 5
Complete the ionic equation for this reaction.
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
Zn + Cu²⁺ → Zn²⁺ + Cu
Step 6
Why is zinc described as being oxidised in this reaction?
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
Zinc is described as being oxidised because it loses two electrons during the reaction.
Step 7
Complete Figure 7 to show how zinc, copper and another substance can be used to light a lamp.
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 diagram should illustrate a complete circuit with labeled zinc and copper electrodes placed in an electrolyte solution, connected to a lamp represented by the symbol ⊗.
