A concentrated aqueous solution of the sodium salt shown is electrolysed between inert electrodes. Which statements are correct?

The compound shown is sodium propanoate. At the anode the propanoate ions lose $\mathrm{CO}{}_2$ and the ethyl radicals dimerise to butane. At the cathode water is reduced to $\mathrm{H}{}_2$ and $\mathrm{OH}{}^{-}$. Ethene is the anode product only for a dicarboxylate salt such as succinate, so statements 1, 2 and 3 are correct.