Magnesium is obtained by the electrolysis of magnesium chloride in a cell similar to the one shown below.
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a) i) What is the cathode made from?<br>ii) What is the anode made from?<br>iii) Why is the chlorine gas kept separate from the magnesium metal?<br>b) The magnesium chloride is made by the following reaction<br>$$\mathrm{MgO + C + Cl_2 \rightarrow MgCl_2 + CO}$$<br>Rewrite the equation in words.<br>c) Name two other metals that are obtained by electrolysis.

(a)(i) The cathode is the iron tank, which is connected to the negative terminal; magnesium is deposited there.<br>(ii) The anode is the graphite rod connected to the positive terminal; chlorine is given off there.<br>(iii) Hot magnesium reacts readily with chlorine, so if the two met they would simply re-form magnesium chloride; keeping them apart also lets the chlorine be collected safely.<br>(b) Magnesium oxide + carbon + chlorine $$\rightarrow$$ magnesium chloride + carbon monoxide.<br>(c) For example sodium and aluminium (potassium, calcium and lithium are also obtained by electrolysis).