identify the species that is oxidized and the species that is reduced in the reaction: 2 I - + CI2 = 2CI - + I2

Answer is: I⁻ is oxidized and Cl₂ is reduced.

Balanced oxidoreduction reaction: 2I⁻ + Cl₂ → 2Cl⁻ + I₂.

Iodine lost electrons and change oxidation number from - 1 (iodine anionI⁻) to oxidation number 0 (iodine molecule I₂).

Chlorine gain electrons and change oxidation number from 0 (molecule of chlorine Cl₂) to oxidation number - 1 (chlorine anion Cl⁻).

Oxidized specie: I2 (iodine)

Reduced specie: 2 Cl - (Chlorine)

Explanation:

Reaction: 2 I - + CI2 → 2CI - + I2

According to the definitions of oxidation and reduction with respect to electron transfer:

Reduced Species are species that absorbs or add electron and gain negative charge or neutral.

Oxidized species are species in reactions that release electrons to gain a positive charge or neutral.

Hence chlorine in this reaction absorbs electron to become Cl-. And iodine release electrons to become neutral. So chlorine is reduced while iodine is oxidized.