Question

Carbon dioxide is not a supporter of combustion.But a burning Mg ribbon continues burning in a gas jar filled with carbon dioxide.Why?

Answer 1

Magnesium is reactive enough to be combusted and oxidized in a reaction with carbon dioxide:

    2 Mg + CO2 -> 2 MgO + C

The magnesium strip burns brightly in the air, but continues to burn in the carbon dioxide environment.

Answer 2

Mg burns in presence of of CO2 because the O2 in co2 is able to b- ond with Mg and produce and oxide. Carbon is formed as a byproduct.

2Mg+O2=2MgO