Question

Electrolysis is performed upon molten MgCl2. platinum electrodes are used. (a) write the cathode and anode half reactions

Answer 1

Explanations:

Electrolysis occur when an electric current is passed through a liquid or solution thereby causing the decomposition of chemicals.

For magnesium chloride, it will be heated to be able to conduct electricity. When molten, the MgCl2 will decomposes into Mg2+ and 2Cl- ions. During electrolysis, the elements are separated according to the equations;

`\begin{gathered} Mg^(2+)+2e^-\rightarrow Mg(s) \\ 2Cl^-\rightarrow Cl_2(g) \end{gathered}`

According to the half reactions, the Mg2+ is reduced at the cathode (-) and the Cl- is oxidized at the anode (+). Reduction at the cathode shows that magnesium gains two electrons to form a magnesium solid while the chlorine ion looses two electrons at the anode