IGCSE Chemistry 0620/42/F/M/21 Q4a-g

Question

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

4 A student wanted to make some zinc chloride crystals.
The student followed the procedure shown.
step 1 Add excess zinc powder to dilute hydrochloric acid to form aqueous zinc chloride.
step 2 Remove unreacted zinc powder from the aqueous zinc chloride.
step 3 Heat the solution until it is saturated.
step 4 Allow the saturated solution to cool and remove the crystals that form.
(a) Write the equation for the reaction in step 1. Include state symbols.
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(b) Explain why excess zinc powder is added in step 1.
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(c) Suggest how unreacted zinc powder is removed in step 2.
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(d) A saturated solution is formed in step 3.
Suggest what is meant by the term saturated solution.
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(e) Explain why crystals form as the solution cools in step 4.
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(f) Name two zinc compounds which react with dilute hydrochloric acid to form zinc chloride.
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(g) If excess calcium metal is used instead of excess zinc powder in step 1, pure calcium chloride crystals do not form.
Explain why.
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    2022-07-05T13:57:13+08:00

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