Which of the following occurs during a redox reaction?

A. Only electrons are obtained

B. Only electrons are lost

C. Electrons are won and lost

D. Electrons are not earned or lost

C = Electrons are won and lost.

Explanation:

The oxidation reduction reactions are called redox reaction. These reactions are take place by gaining and losing the electrons and oxidation state of elements are changed.

Oxidation:

Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.

Reduction:

Reduction involve the gain of electron and oxidation number is decreased.

Consider the following reactions.

4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl

the oxidation state of copper is changed from + 2 to + 1 so copper get reduced.

CO + H₂O → CO₂ + H₂

the oxidation state of carbon is + 2 on reactant side and on product side it becomes + 4 so carbon get oxidized.

Na₂CO₃ + H₃PO₄ → Na₂HPO₄ + CO₂ + H₂O

The oxidation state of carbon on reactant side is + 4. while on product side is also + 4 so it neither oxidized nor reduced.

H₂S + 2NaOH → Na₂S + 2H₂O

The oxidation sate of sulfur is - 2 on reactant side and in product side it is also - 2 so it neither oxidized nor reduced.

Oxidizing agents:

Oxidizing agents oxidize the other elements and itself gets reduced.

Reducing agents:

Reducing agents reduced the other element are it self gets oxidized.