Copper electrodeEleckt

rod kuprum

Cell 1ISel 1I

Aqueous copper (II) sulphateKuprum (II) sulfat akueus

1 Aqueous copper (II) sulphate was electrolysed in two cells using different electrodes as shown in the diagram below. Kuprum (II) sulfat akueus telah dielektrolisiskan di dalam dua sel yang menggunakan elektrod-elektrod yang berbeza seperti yang ditunjukkan dalam rajah di bawah.

Carbon electrodeElecktrod karbon

Cell 1Sel 1

Aqueous copper (II) sulphateKuprum (II) sulfat akueus

(a) Write the formula of all the ions present in the aqueous copper (II) sulphate.

[ 1 mark/ markah]

(b) In Cell 1,

(i) name the gas product formed at the anode and write an equation for the reaction that occurs.

Product/Hasil

Equation/Persamaan

[ 2 marks/ markah](ii) state two observations that would be seen in Cell 1.

nyatakan dua pemerhatian yang dapat dilihat dalam Sel 1.

[ 2 marks/ markah](iii) After the electrolysis had been in progress for 30 minutes, what is the colour of a piece of blue litmus

paper dipped into the solution? Give a reason for your answer.Colour change/Perubahan warna

Reason/Sebab

[ 2 marks/ markah]

(c) In Cell 2,

(i) state a change at the anode.

[ 1 mark/ markah]

(ii) Do you expect to see the same changes of (b)(ii) in Cell 2? Explain your answer. (2m)

4 Diagram below shows the set up of the apparatus with the combination of electrolytic cell and chemical cell.

V

Electrolytic CellSel Elektrolisis

Chemical CellSel Kimia

CopperelectrodeElektrodkuprum

CopperelectrodeElektrodkuprum

ZincelectrodeElektrod

zink

Copper(II) sulphate solutionLarutan kuprum(II) sulfat

(a) Which cell will produce electrical energy?

[ 1 mark/ markah]

(b) Write the formulae of all ions that are present in copper(II) sulphate solution.

[ 1 mark/ markah]

(c) Based on the chemical cell

(i) Label the negative terminal of the cell.

[ 1 mark/ markah]

(ii) State the flow of electron.

[ 1 mark/ markah]

(iii) State the observation at copper electrode.

[ 1 mark/ markah]

(iv) Write half equation for the reaction at cooper.

[ 1 mark/ markah]

(d) Based on the reaction in electrolytic cell.

(i) What is the observation at anode

[ 1 mark/ markah]

(ii) Explain the observation in d(i).

[ 2 marks/ markah]

(iii) Name the product formed at cathode.

X