Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
391–400 of 423 · Normal
Question 391
3 marks · Normal
Answer and see the solution →Describe how the appearance and composition of copper(II) sulfate solution change after it is electrolysed for a long period using inert electrodes.
Question 392
4 marks · Normal
Answer and see the solution →The following table shows the observations at the electrodes during electrolysis of copper(II) sulfate solution with inert electrodes.
(a)[0 marks]Observations during Electrolysis Electrode Observation Cathode Pink/brown coating forms Anode Gas bubbles produced (b)[1 mark]Name the substance forming the pink/brown coating at the cathode.
(c)[1 mark]Name the gas produced at the anode.
(d)[2 marks]Suggest a simple test to confirm the identity of the gas collected at the anode.
Question 393
1 mark · Normal
Answer and check →Which of the following is the correct balanced half-equation for the reaction at the anode during the electrolysis of copper(II) sulfate solution using inert electrodes?
- A.Cu^{2+}(aq) + 2e^- \rightarrow Cu(s)
- B.2Cl^-(aq) \rightarrow Cl_2(g) + 2e^-
- C.4OH^-(aq) \rightarrow 2H_2O(l) + O_2(g) + 4e^-
- D.H^+(aq) + e^- \rightarrow H_2(g)
Question 394
2 marks · Normal
Answer and see the solution →Explain why oxygen gas is produced at the anode during the electrolysis of copper(II) sulfate solution with inert electrodes.
Question 395
4 marks · Normal
Answer and see the solution →Copper(II) sulfate solution is electrolysed using inert electrodes for a long time.
(a)[2 marks]Describe what happens to the colour of the solution.
(b)[2 marks]Explain why these changes occur.
Question 396
2 marks · Normal
Answer and see the solution →State the products formed at the cathode and at the anode when dilute sodium sulfate solution is electrolysed using inert electrodes.
Question 397
4 marks · Normal
Answer and see the solution →Potassium chloride solution is electrolysed using inert electrodes.
(a)[1 mark]State whether hydrogen or potassium is formed at the cathode.
(b)[2 marks]Explain why this product is formed at the cathode, using the reactivity series.
(c)[1 mark]Name the product formed at the anode.
Question 398
3 marks · Normal
Answer and see the solution →Electrolysis of aqueous copper(II) nitrate solution was carried out using inert electrodes. No copper was deposited at the cathode.
Explain which products are formed at the cathode and anode, and why these products are formed.
Question 399
4 marks · Normal
Answer and see the solution →The table shows part of the reactivity series and the likely product at the cathode during the electrolysis of an aqueous solution of the metal compound.
Metal Relative position (above/below H) Product at cathode Potassium Above Hydrogen Copper Below ? Sodium Above Hydrogen Silver Below ? a) Complete the column for 'Product at cathode' for copper and silver.
b) Explain, using the reactivity series, why these products are formed for copper and silver.
(a)[2 marks](b)[2 marks]Question 400
1 mark · Normal
Answer and check →Which of the following anions will produce oxygen gas at the anode, rather than a halogen, during electrolysis of an aqueous solution?
- A.Chloride (Cl⁻)
- B.Bromide (Br⁻)
- C.Sulfate (SO₄²⁻)
- D.Iodide (I⁻)