Answer :
Ethanol 
act as reducing agent.
The smallest possible integer coefficient of 
in the combined balanced equation is, 4
Explanation :
Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.
Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.
Reducing agent : It is defined as the agent which helps the other substance to reduce and itself gets oxidized. Thus, it will undergo oxidation reaction.
Oxidizing agent : It is defined as the agent which helps the other substance to oxidize and itself gets reduced. Thus, it will undergo reduction reaction.
The given chemical reaction is,
The oxidation-reduction half reaction will be :
Oxidation : 
Reduction : 
- Now balance oxygen atom on both side.
Oxidation : 
Reduction : 
- Now balance hydrogen atom on both side.
Oxidation : 
Reduction : 
Oxidation : 
Reduction : 
In order to balance the electrons, we multiply the oxidation reaction by 5 and reduction reaction by 4 and then added both equation, we get the balanced redox reaction.
Oxidation : 
Reduction : 
The balanced chemical equation in acidic medium will be,
In the redox reaction ethanol act as reducing agent and permanganate ion act as an oxidizing agent.
