11.4The Reactions of Chlorine

Flashcards summarizing key concepts related to the reactions of chlorine, including disproportionation reactions, half-equations, and their applications in water purification.

What is a disproportionation reaction?

A reaction in which the same species is both oxidized and reduced.

What happens to chlorine in a disproportionation reaction with dilute alkali at 15 °C?

Chlorine is both oxidized and reduced, forming NaCl and NaClO.

What is the ionic equation for the reaction of chlorine with dilute alkali at cold temperature?

Cl (aq) + 2OH (aq) → Cl (aq) + ClO (aq) + H2O (l).

What is the oxidation half-equation when chlorine reacts in cold alkali?

½Cl (aq) + 2OH (aq) → ClO (aq) + H2O (l) + e-.

What is the reduction half-equation when chlorine reacts in cold alkali?

½Cl (aq) + e- → Cl- (aq).

At what temperature do you get a different reaction for chlorine with dilute alkali?

At 70 °C.

What is the reaction that takes place when chlorine reacts in hot alkali?

3Cl (aq) + 6NaOH (aq) → 5NaCl (aq) + NaClO (aq) + 3H2O (l).

What is the ionic equation for the disproportionation reaction of chlorine in hot alkali?

3Cl (aq) + 6OH (aq) → 5Cl- (aq) + ClO3- (aq) + 3H2O (l).

In the context of chlorine reactions, what does oxidation number increase indicate?

An increase in oxidation number indicates that the species is being oxidized.

What is chloric(I) acid and how does it relate to water purification?

Chloric(I) acid (HClO) is produced when chlorine is added to water and acts as a sterilizing agent.

How does chloric acid (HClO) dissociate in water?

HClO (aq) → H+ (aq) + ClO- (aq).

What is the significance of adding chlorine to a water supply?

It effectively makes the water safe to drink by forming sterilizing agents.

What is the relationship between HClO and ClO - in water purification?

HClO forms ClO - upon dissociation, which acts as a sterilizing agent.