Oxidation-Reduction Reactions Quiz

What memory aid is used to summarize the processes of oxidation and reduction?

What defines the fundamental difference between oxidation and reduction?

What happens to sulphites when chlorine is added, and why is chlorine classified as an oxidising agent?

What is observed when dilute HCl is added to a sulphite solution after a white precipitate has formed with BaCl₂?

What color precipitate is formed when NaOH is added to a solution containing Fe²⁺?

What is a common characteristic of all halogens?

What is the expected observation when chlorine is added to a Fe(II) solution?

What describes the role of an oxidising agent in a chemical reaction?

Which equation represents the reaction involving Cl₂ and KBr?

What is the purpose of adding BaCl₂ to a sulphite solution?

Oxidation and Reduction

OILRIG is a mnemonic for remembering oxidation and reduction: Oxidation is Loss, Reduction is Gain of electrons.
Oxidation involves the loss of electrons; reduction involves the gain of electrons.

Chemical Tests for Sulphites

BaCl₂ is added to a sulphite solution to test for sulphites; a white precipitate forms if sulphites are present.
Dilute HCl is then added to dissolve the white precipitate formed with BaCl₂; expected observation is that the precipitate dissolves.

Chlorine as an Oxidizing Agent

Chlorine acts as an oxidizing agent because it facilitates oxidation by accepting electrons during reactions.
When chlorine is added to a sulphite solution, it oxidizes sulphite into sulfate.

Testing for Iron Ions

The test for Fe²⁺ ions aims to confirm the absence of Fe³⁺; when 10 drops of NaOH are added to a solution with Fe²⁺, a green precipitate forms.
Chlorine addition to an Fe(II) solution results in a red-brown precipitate due to the formation of Fe(III).

Halogens and Their Properties

All halogens are classified as oxidizing agents, with their oxidizing ability diminishing as one moves down the group in the periodic table.

Role of Chemical Agents

An oxidizing agent is required in a chemical reaction to facilitate oxidation through the acceptance of electrons.
A reducing agent allows reduction to occur by donating electrons.

Key Reactions and Observations

The reaction of Cl₂ with KBr leads to a color change from colorless to orange.
Cl₂ reacts with KI, resulting in a color change from colorless to red/brown.
Br₂ and KI also react, changing from colorless to red/brown.

Test your knowledge on oxidation and reduction reactions, including the definitions and characteristics of these processes. This quiz also covers practical aspects, such as reactions involving sulfur compounds and the role of chlorine as an oxidizing agent.