Draw a fully labelled diagram that illustrates how the standard electrode potential, E^circ, of X^{2+}(aq)/X(s) could be measured.
What conditions must be in place for the value measured to count as a standard electrode potential?
State the charge carriers responsible for current in the solutions, and in the wire.
An electrochemical cell consisted of an X^{2+}(aq)/X(s) half-cell (E^\circ = -0.40\ \text{V}) together with an Ag^+(aq)/Ag(s) half-cell (E^\circ = +0.80\ \text{V}). Write an equation for the reaction that would occur if the electrodes in this cell were joined by a wire.
While the current was allowed to flow for a period of time, the Ag electrode increased in mass by 1.30\ \text{g} and the electrode made of metal X decreased in mass by 0.67\ \text{g}. Calculate the A_r of metal X; hence suggest an identity for X. Show all your working. Use of the Data Booklet is relevant to this question.