Question

Electrolysis is the breakdown of an ionic compound by the passage of electricity.
(a) Complete the following sentences about the products of electrolysis.
Choose words from the list.

                                   electrolytes
                                     hydrogen
                                      negative
                                       neutral
                                   non-metals
                                     positive

During electrolysis of aqueous solutions, metals or ……….. are formed at the cathode. The anode is the ………… electrode where ………….. are formed.

(b) Aqueous copper(II) sulfate can be electrolysed using copper electrodes or using carbon (graphite) electrodes.
     (i) State the product formed at the anode when aqueous copper(II) sulfate is electrolysed using each type of electrode.
         copper electrodes ………………………………………………………………………………………………..
         carbon (graphite) electrodes …………………………………………………………………………………

     (ii) Fig. 11.1 shows the change in mass at the cathode when aqueous copper(II) sulfate is electrolysed using copper electrodes.

            The investigation is done using different currents, each for the same length of time.

         Predict the change in mass of the anode when the current is 0.25A.

          change in mass of anode = ……………………. g

    (iii) Construct the ionic half‐equation for the formation of the product at the cathode using carbon (graphite) electrodes.