Identify the missing component of the cell and its function.

Deduce the half-equations for the reaction at each electrode when current flows.

Annotate the diagram with the location and direction of electron movement when current flows.

Calculate the cell potential, in V, using section 24 of the data booklet.

Determine the loss in mass of one electrode if the mass of the other electrode increases by 0.10 g.

salt bridge

movement of ions

OR

balance charge

Do not accept “to complete circuit” unless ion movement is mentioned for M2.

[2 marks]

Positive electrode (cathode):

Ag⁺(aq) + e^– → Ag(s)

Negative electrode (anode):

Mg(s) → Mg²⁺(aq) + 2e^–

Award [1 max] if correct equations given at wrong electrodes.

[2 marks]

in external wire from left to right

[1 mark]

«E = +0.80 V – (–2.37 V) = +» 3.17 «V»

[1 mark]

«moles of silver \(\frac{{0.10{\text{ g}}}}{{107.87{\text{ g mo}}{{\text{l}}^{ - 1}}}}\)»

moles of magnesium \( = \frac{{0.5 \times 0.10{\text{ }}\ll {\text{g}}\gg }}{{107.87{\text{ }}\ll {\text{g mo}}{{\text{l}}^{ - 1}}\gg }}\)

«loss in mass of magnesium \( = \frac{{24.31{\text{ g mol}} \times 0.5 \times 0.10{\text{ g}}}}{{107.87{\text{ g mo}}{{\text{l}}^{ - 1}}}} = \)» 0.011 «g»

Award [2] for correct final answer.

[2 marks]