Distinguish among primary secondary and tertiary alcohol
Answers
Answer:
What is Secondary Alcohol?
Secondary alcohols are the alcohols in which hydroxyl group is attached to the secondary carbon atom of the alcohol molecule. Secondary alcohols are converted into ketones (R2CO) upon oxidation under mild condition. Stronger oxidants, however, lead to the formation of acids or mixture of acids. With Lucas test, secondary alcohols form oily layers within about five minutes. Secondary alcohols are more stable and more reactive than primary alcohols. However, secondary alcohols are less acidic than primary alcohols. Some examples of secondary alcohol include isopropyl alcohol and butyl alcohol.

Figure 02: Secondary Alcohol
Difference Between Primary and Secondary Alcohol
Definition
Primary Alcohols: Primary alcohol is an alcohol which has the hydroxyl group connected to a primary carbon atom.
Secondary Alcohols: Secondary alcohol is an alcohol which has the hydroxyl group on a secondary carbon atom.
Reactivity
Primary Alcohols: Primary alcohols are less reactive than secondary alcohols.
Secondary Alcohols: Secondary alcohols are more reactive than primary alcohols.
Esterification
Primary Alcohols: Rate of esterification is highest in primary alcohols.
Secondary Alcohols: Rate of esterification is less in secondary alcohols.
Easiness of Dehydration
Primary Alcohols: Primary alcohols are difficult to dehydrate than secondary alcohols.
Secondary Alcohols: Secondary alcohols are easier to dehydrate.
Dehydrogenation
Primary Alcohols: Primary alcohols result in aldehydes and hydrogen.
Secondary Alcohols: Secondary alcohols results in ketones and hydrogen.
Lucas Test
Primary Alcohols: Primary alcohols do not form oily layers.
Secondary Alcohols: Primary alcohols form oily layers within about five minutes.
Stability
Primary Alcohols: Primary alcohols are less stable than secondary alcohols.
Secondary Alcohols: Secondary alcohols are more stable.
Victor Meyer’s Test
Primary Alcohols: Primary alcohols give a blood red color.
Secondary Alcohols: Secondary alcohols give a blue color.
Acidity
Primary Alcohols: Primary alcohols are more acidic than secondary alcohols.
Secondary Alcohols: Secondary alcohols are less acidic.
Summary
Primary and secondary alcohols are two types of alcohols coming under monohydric alcohols. In primary alcohols, -C-OH group is attached one carbon atom, whereas, in secondary alcohols, -C-OH group is attached to another two carbon atoms. Based on this main difference between primary and secondary alcohols, their properties vary. Lucas test and Victor Meyer’s test are used to identifying primary and secondary alcohols.
Reference:
1.Johnson, A. W. (1999). Invitation to organic chemistry. Jones & Bartlett Learning.
2.Madan, G. (2005). S. Chands Success Guide (Q&A) Inorganic Chemistry. S. Chand Publishing.
3.Competition Science Vision, 2003, Vol.5, Pratiyogita Darpan Group, India
Image Courtesy:
1. “Methanol flat structure” By Cacycle – Own work (Public Domain) via Commons Wikimedia
2. “Secondary alcohol” By Skend – Own work (Public Domain) via Commons Wikimedia