GCSE Edexcel Chemistry The Process of Electrolysis: 3 (a) Some metals are extracted

Question

3 (a) Some metals are extracted by the electrolysis of a molten compound.

(i) Complete the sentences about the electrolysis of a molten compound using words from the box.

Each word may be used once, more than once or not at all.

- decomposed
- electricity
- electrons
- ions
- molecules
- purified

The compound has to be molten so that the **ions** can move.

When a molten compound is electrolysed its elements are formed. During electrolysis the compound is **decomposed**.

(ii) Which of the following statements about electrolysis is correct? Put a cross (X) in the box next to your answer.

- A an ion is positively charged
- B an anion is negatively charged
- C a cation is positively charged
- D a cathode is positively charged

**C** a cation is positively charged.

(b) When molten zinc chloride is electrolysed, a solid forms at one electrode and a pale green gas forms at the other electrode.

Use this information to complete the word equation for the reaction that takes place when molten zinc chloride is electrolysed.

**zinc chloride → zinc + chlorine**

(ii) In this electrolysis, chloride ions lose electrons to form the pale green gas.

State the type of reaction that occurs when electrons are lost.

**oxidation**

(c) Copper chloride dissolves in water.

Describe what you see when sodium hydroxide solution is added to a solution containing copper ions, Cu²⁺.

**(pale) blue precipitate/solid.**

(d) Sodium is manufactured by the electrolysis of molten sodium chloride.

Explain a large-scale use of sodium.

**(uses in) street (lamps/lights), yellow (light is produced from sodium vapour) or nuclear reactors (good conductor of heat/coolant).**

3 (a) Some metals are extracted by the electrolysis of a molten compound - Edexcel - GCSE Chemistry - Question 3 - 2016 - Paper 1