All Organic Chemistry Resources
Example Questions
Example Question #1 : Oxidation Reduction Reactions
Which of the following is NOT an oxidizing agent?
Ozone
Osmium tetroxide
Potassium permanganate
Chromic acid
The answer is .
Lindlar's catalyst enables catalytic hydrogenation, specifically for an alkyne to reduce to a cis-alkene (though the reaction does not continue to produce an alkane). The rest of the answer options are oxidizing agents.
Example Question #1 : Help With Oxidation
A water molecule is converted to hydrogen peroxide through a series of reactions. What can you conclude about the oxygen molecule?
Oxygen is reduced because it loses an electron
Oxygen is oxidized because it loses an electron
Oxygen is oxidized because it gains an electron
Oxygen is reduced because it gains an electron
Oxygen is oxidized because it loses an electron
Water, , has an oxygen atom with an oxidation number of
whereas hydrogen peroxide,
, has an oxygen atom with an oxidation number of
. A less negative oxidation number suggests that the oxygen lost an electron. Recall that oxidation is the loss of electrons whereas reduction is the gain of electrons; therefore, the oxygen atom lost an electron and was oxidized when water was converted to hydrogen peroxide.
Example Question #2 : Oxidation Reduction Reactions
Which of the following is true regarding oxidation?
I. Oxidation increases the oxidation number
II. Oxidizing agent is always reduced
III. Oxidation of an atom is always spontaneous
I and II
III only
II and III
I and III
I and II
Oxidation is the process of removing electrons from an atom. This increases the oxidation number (makes oxidation number more positive). An atom undergoes oxidation by losing electrons and donating them to another atom. Since it is facilitating reduction (gain of electrons) of another atom, an atom that is oxidized is also called a reducing agent. Oxidizing agents, on the other hand, are reduced (gain electrons) and facilitate the oxidation of other atoms (removal of electrons from other atoms). Oxidation of an atom does not depend on the Gibbs free energy; therefore, oxidation can be spontaneous or nonspontaneous.
All Organic Chemistry Resources
![Learning Tools by Varsity Tutors](https://vt-vtwa-app-assets.varsitytutors.com/assets/problems/og_image_practice_problems-9cd7cd1b01009043c4576617bc620d0d5f9d58294f59b6d6556fd8365f7440cf.jpg)