Classical Idea Of Redox Reactions Oxidation And Reduction Reactions

In the given reaction, KMnO₄ acts as an oxidizing agent, and iodide (I^-) is oxidized to iodate (IO₃^-). In an alkaline or neutral medium, the balanced equation for the oxidation process is as follows:

2 KMnO₄ + H₂O + I^- → 2 MnO₂ + 2 KOH + IO₃^-

To determine the change in the oxidation state of manganese (Mn), let's analyze its transformation in the reaction:

• In KMnO₄, Mn is in the +7 oxidation state.
• In MnO₂, Mn is in the +4 oxidation state.

Thus, the change in the oxidation state of manganese is from +7 in KMnO₄ to +4 in MnO₂.

The correct answer to the change in oxidation state of manganese is (+7 to +4).

To determine which reaction is NOT a redox reaction, we must understand what constitutes a redox reaction. In a redox (reduction-oxidation) reaction, there is a transfer of electrons between species, leading to changes in their oxidation states. We'll analyze each option to check the oxidation state changes:

Zn + CuSO₄ → ZnSO₄ + Cu

Zinc (Zn) is oxidized from 0 to +2 and copper (Cu) is reduced from +2 to 0. This is a redox reaction.

2KClO₃ + I₂ → 2KIO₃ + Cl₂

Chlorine changes from +5 in KClO₃ to 0 in Cl₂ (reduction), and iodine changes from 0 to +5 in KIO₃ (oxidation). This is a redox reaction.

H₂ + Cl₂ → 2HCl

Hydrogen changes from 0 to +1, and chlorine changes from 0 to -1. This is a redox reaction.

BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl

No change in oxidation states for barium, sodium, or chloride as both sides have the same oxidation numbers. This is a double displacement reaction, not a redox reaction.

The reaction: BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl is NOT a redox reaction.

Potassium permanganate (KMnO ) is a strong oxidizing agent. It can oxidize alkanes, but it selectively oxidizes tertiary carbons (carbons bonded to three other carbon atoms) to alcohols. In the given reaction, the carbon atom bonded to the hydrogen atom that is being replaced by the hydroxyl group (-OH) must be a tertiary carbon for the oxidation to occur.
Let's examine the options:
(1) If all R groups are hydrogen atoms, the carbon is primary (bonded to only one other carbon).
(2) If all R groups are methyl groups (CH ), the carbon is tertiary (bonded to three other carbons).
(3) If R is a methyl group and the other R groups are hydrogen, the carbon is primary.
(4) If R and R are methyl groups and R is hydrogen, the carbon is secondary (bonded to two other carbons).
Only option (2), where all R groups are methyl groups, results in a tertiary carbon that can be oxidized by KMnO to the corresponding alcohol.