10 minutes maximum! Can you do it in 5?

1. The products at the electrodes in the electrolysis of molten potassium iodide are:

Q2-5. Electrolysis of molten lead bromide is carried out using the following circuit:

2. The current is carried around the circuit by:

• A. solid lead bromide is covalently bonded
• B. solid lead bromide is too tightly packed for electrons to get through
• C. the ions in solid lead bromide are not free to move around
• D. the atoms in solid lead bromide are not free to move around

4. The balanced half-equation and the type of reaction occurring at the negative electrode is:

5. The balanced half-equation and the type of reaction occurring at the positive electrode is:

Q6-7.   Four substances were dissolved in water and connected in turn into the circuit below.

The results are shown in the table:

6. Which solution could be sulphuric acid?

7. Which solution could be copper(II)nitrate ?

Q8-9.
The electrolysis of a concentrated solution of sodium chloride produced two gases, X and Y :

8. The identity of gas X and a test to confirm its identity is:

• A. H⁺ + e^- → H
• B. 2H⁺ + 2e^- → H₂
• C. 2H⁺ → H₂ + 2e^-
• D. Na⁺ + e^- → Na

10. Aluminium is extracted by the electrolysis of molten aluminium oxide, Al₂O₃.