Question

The reaction for the combustion of acetylene is shown. Explain why this reaction is a redox reaction by identifying the oxidation numbers that change, what is oxidized, what is reduced, and what happens to the electrons during the reaction.
2C2H2 + 5O2 → 4CO2 + 2H2O

Answer 1

2С⁻¹₂Н₂ + 5O⁰₂ → 4C⁺⁴O⁻²₂ + 2Н₂О⁻²

the oxidation process:
С⁻¹ - 5e⁻ = C⁺⁴   carbon is the reducing agent

the reduction process:
O⁰₂ + 4e⁻ = 2O⁻²   oxygen is the oxidizer

Answer 2

Explanation:

Redox reaction: In this type of reaction, oxidation and reduction reaction occurs simultaneously in same chemical reaction.

$2C_2H_2+5O_2\rightarrow 4CO_2 + 2H_2O$

This reaction is a redox reaction :

• Removal of hydrogen or addition of oxygen is termed as oxidation.  in above reaction, removal hydrogen from acetylene gives carbon-dioxide.

• Removal of oxygen or addition of hydrogen is termed as reduction.  in above reaction, removal of one oxygen atom from oxygen molecule with addition of two hydrogen atoms gives water

The oxidation number of carbon in acetylene is -2.

The oxidation number of carbon in carbon-dioxide= +4

Oxidation number of carbon increases after the reaction which means that carbon is getting oxidized.

The oxidation number of oxygen in oxygen gas = 0

The oxidation number of oxygen in water = -2

Oxidation number of oxygen decreases after the reaction which means that oxygen is getting reduced.

The electrons released during oxidation are transferred to the species which are undergoing reduction reaction.