Question

In terms of electron gain and loss, and half equations why is Cl2+2NaI -> 2NaCl+I2 a redox reaction? (6 mark question)

Answer 1

Consider,

`Cl_2 + 2NaI to 2NaCl + I_2`

having two half reactions, one reduction and one oxidation, in turn,

`Cl_2 rightleftharpoons 2Cl^(-)`, and

`2I^(-) rightleftharpoons I_2`

To be sure, the chlorine diatomic molecule is being reduced into two chloride ions that ionically bond with the sodium ions left over from the iodide ions being oxidized. The source of electrons are the iodide ions, which go toward reducing the chlorine diatomic molecule.