DP Chemistry (last assessment 2024)

Test builder »

Question 18M.2.sl.TZ2.3c.ii

Select a Test
Date May 2018 Marks available [Maximum mark: 2] Reference code 18M.2.sl.TZ2.3c.ii
Level sl Paper 2 Time zone TZ2
Command term Formulate Question number c.ii Adapted from N/A
c.ii.
[Maximum mark: 2]
18M.2.sl.TZ2.3c.ii

The emission spectrum of an element can be used to identify it.

(c.ii)

Impure copper can be purified by electrolysis. In the electrolytic cell, impure copper is the anode (positive electrode), pure copper is the cathode (negative electrode) and the electrolyte is copper(II) sulfate solution.

Formulate the half-equation at each electrode.

 

[2]

Markscheme

Anode (positive electrode):

Cu(s) → Cu2+(aq) + 2e–

Cathode (negative electrode):

Cu2+(aq) + 2e– → Cu(s)

 

Accept Cu(s) – 2e– → Cu2+(aq).

Accept ⇌  for →

Award [1 max] if the equations are at the wrong electrodes.

[2 marks]

Syllabus sections