Question

Question #880a8

Answer 1

Under alkaline conditions manganate(VII) will oxidise unsaturated hydrocarbons such as alkenes to a diol.

I'll use ethene as an example

The first step is that purple Mn(VII) are reduced to green Mn(VI) ions:

`CH_2=CH_2 +2MnO_4^(-)+2OH^(-)rarrHOCH_2CH_2OH+2MnO_4^(2-)`

Ethane - 1,2 - diol is formed and green `MnO_4^(2-)`.

The reaction then continues to give dark brown solid manganese(IV) oxide:

`3CH_2CH_2+2MnO_4^(2-)+4H_2Orarr3(HOCH_2CH_2OH)+2MnO_2+2OH^-`