Week 4 discussion
1. a) Define oxidation and reduction reactions in terms of Organic Chemistry; b) Discuss the various oxidation states of C and give an example of each.
Ans-a) Normally, oxidation and reduction are the processes by which the elements undergo a net loss or gain of electrons. The net loosing of electrons is called oxidation and the respective addition of electrons is known as reduction. According to Norman & Pringle 2022, in organic chemistry, the concept of oxidation and reduction is such that the electrons share their electrons instead of losing or gaining as in inorganic compounds. Here, the carbon atoms gain bonds to the more electronegative element like oxygen, and in reduction, the carbon is attached to a less electronegative atom like hydrogen. (Nadkarni, et al 2022).
For example: OXIDATION: CH4 → CH3OH [O]
REDUCTION: CH3OH → CH4 [RED]
Here the central carbon (functional group) is transferred to highly oxidized carbon and in reduction central carbon is attached to the reduced form.
- b) The various oxidation states of Carbon are as follows:
- i) For example methane CH4 has 4 hydrogen having +1 charge whereas carbon has -4 charge in compared to hydrogen.
Therefore, the oxidation state of carbon will be 1*(-4) =-4
- ii) CH3CH2CH=CH2 has two hydrogens attached to the last carbon and has a charge of +2 and carbon is -2 in this context.
Therefore, the oxidation state of carbon =1*(-2) =-2
iii) Aldehyde has oxygen and carbon where carbon has -1 and oxygen has -2
Therefore, the oxidation states of carbon= -1+2=+1
- iv) Ketones have oxygen and carbon i.e. +1*2=+2
- v) Carbon tetrachloride has an oxidation state of carbon =+1*4=4.
2. Discuss the various classes of alcohol and provide a reaction specific to each class. Give examples and use actual structures
Ans- The various classes of alcohols are:-
- First of all, alcohols are divided into 2 classes:- i) Aliphatic alcohols, ii) Aromatic alcohols
In aliphatic alcohols, hydrogen atoms are exchanged by hydroxyl groups like methane when reacted with oh methyl alcohol formed.
In aromatic alcohol, one or more hydrogen atoms of the side chain are substituted by the hydroxyl group.
On the basis of the hydroxyl group present alcohols can be classified into 4 groups:- monohydric, dihydric, trihydric, and polyhydric alcohols.
Monohydric alcohols are further divided into 3 categories:-
- i) Primary alcohol
- ii) Secondary alcohol
iii) Tertiary alcohol
In primary alcohol, the hydroxyl alcohol group is attached to the primary carbon atom CH2OH. It is 1 degree carbon.
Example: CH3OH (Methanol)
In secondary alcohol, the hydroxyl group is attached to secondary carbon atoms bonded to two other carbon atoms. It is 2 –degree carbon.
For example CH3CHCH3OH (ISOPROPYL ALCOHOL)
CH3CH2OHCH2CH3 (SECONDARY ALCOHOL)
In tertiary alcohols, the hydroxyl group is joined to a tertiary carbon atom and is 3 –degree carbon.
For example:- CH3CCH3CH3OH (Tiertary butyl alcohol)
Norman, N. C., & Pringle, P. G. (2022). In defence of oxidation states. Dalton Transactions.
Nadkarni, A., Tu, A., Garg, A., Gupta, D., Gupta, S., Bhatia, U., … & Velleman, R. (2022). Alcohol use among adolescents in India: a systematic review. Global Mental Health, 9.