11. Oxidation and Reduction Reactions

Question 1

What are the two rules for assigning reduction and oxidation numbers that you need to remember?

Answer 1

Any free element or diatomic species has an oxidation number of zero. (e.g. N2, P4, and S8 all have a number of 0)

The oxidation number of a monatomic ion is equal to the charge of the ion.

Question 2

True or false: the Oxidation Number is the same as the formal charge

Answer 2

FALSE: The oxidation number is not the same as the formal charge.

Question 3

What is being reduced and what is being oxidized in the following reaction?

a. Zn + Cu⁺² –> Zn⁺² + Cu

Answer 3

Oxidation: Zn
Reduction: Cu

Question 4

What is a disproportionation (dismutation) reaction?

Answer 4

Disproportionation (dismutation) reactions are a type of redox reaction in which one element is both oxidized and reduced, forming at least two molecules containing the element with different oxidation states.

Essentially, a decomposition reaction.

Question 5

What is the difference between complete ionic equation and the net ionic equation?

Answer 5

Complete ionic equation accounts for all the ions present in a reaction. You split all compounds into their relevant ions, but keep the SOLID salts intact.

A spectator ion is a ion that **doesn’t change its charge **

A net ionic equation is one that ignores all the spectator ions and focuses only on the species that actually participate in the reaction.

Question 6

Answer 6

The 10 g was not needed in this question.