Balancing Oxidation-Reduction Equations Quiz

Questions and Answers

Which statement best describes what is taking place in the half reaction Fe --> Fe2+ + 2e-?

Iron is being reduced.

Iron is combining with oxygen.

Iron is in a neutral state.

Iron is being oxidized. (correct)

What step should be completed immediately after finding the oxidation states of atoms when using the half-reaction method?

Identifying the half reactions.

Which half reaction correctly describes the oxidation taking place in the reaction Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)?

Zn(s) --> Zn2+(aq) + 2e-

What is the overall equation for the chemical reaction represented by the half reactions Zn --> Zn2+(aq) + 2e- and Cu2+(aq) + 2e- --> Cu(s)?

Zn(s) + Cu2+(aq) --> Zn2+(aq) + Cu(s) Signup and view all the answers

What is the purpose of finding oxidation states in the half-reaction method for balancing equations?

To identify the half reactions for the equation. Signup and view all the answers

The reaction H2 + O2 --> 2H+ + O2- is balanced for charge and number of atoms.

False Signup and view all the answers

What is the coefficient of silver in the final, balanced equation for the reaction Ag+(aq) + Al(s) --> Ag(s) + Al3+(aq)?

3 Signup and view all the answers

Which half-reaction correctly describes an oxidation?

Cr(s) --> Cr3+(aq) + 3e- Signup and view all the answers

Which statement best describes what is taking place in the half reaction Cu2+(aq) + 2e- --> Cu(s)?

Copper is being reduced. Signup and view all the answers

What is an important step in the alternate method for balancing equations in redox reactions?

Determining the half reactions of chemical equations. Signup and view all the answers

Study Notes

Oxidation-Reduction Reactions

In the half reaction Fe → Fe²⁺ + 2e⁻, iron is oxidized as it loses electrons.
The half-reaction method balances equations by breaking them into oxidation and reduction components.

Steps for Balancing Equations

After determining oxidation states of atoms, the next step is identifying the respective half reactions in the redox process.

Half Reactions in Redox Reactions

For the reaction Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g), the oxidation half-reaction is Zn(s) → Zn²⁺(aq) + 2e⁻.
In a paired half reaction system, Zn is oxidized while Cu²⁺ is reduced, resulting in the overall reaction: Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s).

Purpose of Oxidation States

Finding oxidation states helps in identifying the half reactions needed for balancing equations in the redox method.

Balancing Charge and Atom Count

The reaction H₂ + O₂ → 2H⁺ + O₂⁻ is unbalanced concerning charge and atom count, indicating an error in the stoichiometry.

Coefficients in Balanced Equations

In the redox reaction Ag⁺(aq) + Al(s) → Ag(s) + Al³⁺(aq), the coefficient of silver in the balanced equation is 3, reflecting the stoichiometric needs of the reaction.

Identifying Oxidation

An example of an oxidation half-reaction is Cr(s) → Cr³⁺(aq) + 3e⁻, where chromium loses electrons.

Reduction in Half Reactions

The half reaction Cu²⁺(aq) + 2e⁻ → Cu(s) depicts reduction, as copper gains electrons to form solid copper.

Importance of Half Reactions

Determining half reactions is essential in the alternative method for balancing redox equations, ensuring proper tracking of electron transfer.

Description

Test your knowledge on balancing oxidation-reduction equations with this quiz. Understand half-reactions, oxidation states, and the process of identifying reactions. Perfect for students looking to sharpen their chemistry skills.