Question

Al2O3 + 3Mg ⇒ 3MgO + 2Al, in this reaction Mg acts as

1. reducing agent

2. oxidising agent

3. purification agent

4. combustion agent

Answer 1

we know that addition of oxygen is known as oxidation...so

in reaction...

=) Al2O3 +3Mg =) 3MgO +2Al

we can see that addition of oxygen takes place with magnesium(Mg) so magnesium goes oxidation ...

and , we know that ,the element goes oxidation acts as reducing agent..

so Mg acts as a reducing agent..

Answer 2

Al2O3 + 3Mg → 3MgO + 2Al

first of all understand ,
reducing agent or oxiding agent

oxiding agent :- oxiding agent helps in oxidation of other species by accepting electrons lost during oxidation and itself gets reduced .

reducing agent just opposite to oxiding agent .

here we that Mg lost electron and oxidise so, this is reducing agent because reducing agent get oxidised itself .