Question

For the reaction 2Fe+3Cl2=2FeCl3

Answer 1

The question is incomplete but the full question may be found in other sources.

This is the complete question:

• For the reaction 2Fe + 3Cl₂ → 2FeCl₃ which option is more accurate?

        a. FeCl₃, reducing agent; Fe, oxidizing agent.

        b. Cl₂, oxidising agent; Fe reducing agent.

        c. Fe, reducing agent; FeCl₃, oxidizing agent.

        d. FeCl₃, oxidizing agent, Cl₂, reducing agent.

Answer:

• Option b. Cl₂, oxidising agent; Fe reducing agent.

Explanation:

It is easy to recognize by simple inspection that the given reaction is a redox one (oxidation - reduction) because the substances in the reactant side are pure elements (whose oxidation state is always zero) and the substance in the product side is a compound formed by the two reactant elements (which means that now they have a different oxidation state).

In a redox reaction, the element that increases its oxidation number loses electrons and reduces other element, so this is the reducing agent. On the other hand, the element whose oxidation number is decreased has gained electrons, a so it is the oxidizing agent (it oxidizes other element).

I will show the oxidation states of each species in the chemical reaction, using superscripts:

• Fe⁰ + 3Cl₂⁰ → 2 Fe⁺³Cl₃⁻¹

Thus:

• 2 atoms of Fe increased their oxidation number from 0 to +3; meaning that they lost 6 electrons (3 electrons each), so Fe is the reducing agent (it reduced the Cl atoms).

• 6 atoms of Cl decreased their oxidation number from 0 to -1; meaning that they gained 6 electrons in total (1 elecron each), so Cl is the oxidizing agent (it oxidized the Fe atoms).