Question

The correct order of boiling point of 1, 2 and 3 alcohol is:
A. 1 > 2 > 3.
B. 3 > 2 > 1.
C. 2 > 1 > 3.
D. 2 > 3 > 1.

Answer 1

Hint: In this issue, we should be aware that a primary alcohol is an alcohol in which, by comparison, the hydroxyl group is bound to a main carbon atom, a secondary alcohol has a formula and a tertiary alcohol has a formula in which "R" indicates a carbon-containing ring.

Complete step-by-step answer:
Alcohol is an organic compound which carries at least one functional hydroxyl group (−OH) binding to a saturated carbon atom. Originally the term alcohol applied to the primary alcohol ethanol ( ethyl, alcohol ), which is used as a medicine that is the main alcohol in alcoholic drinks. Not only hydrogen bonds, but also van der Waals dispersion forces and dipole-dipole interactions are the factors influencing the boiling / melting points of alcohols.
The hydrogen bonds and the dipole-dipole interactions throughout the series of alcohols will remain relatively the same. The dispersion forces of the van der Waals increase with the length of the hydrocarbon chain. It is due to the change in the number of electrons in the molecules, which in effect increases the frequency and scale of the dipole-dipole attraction temporarily inducted. Therefore, more energy is required to resolve the intermolecular forces, resulting in boiling / melting points.
It is predicted that alcohols of the same molecular weight would have almost a boiling point, but two factors other than molecular weight are significant, namely H-bonding and molecular surface area. Both of these factors are lowest in $3^0$ alcohols and highest in $1^0$ alcohols. Therefore $3^0$ alcohols have a boiling point at least while $1^0$ alcohols have a boiling point at maximum.
Hence, the proper boiling point order is 1 > 2 > 3.
So choice (A) is the correct one.

Note: Whenever we ask questions of this type, we must first know the basic concept of alcohol 1, 2 and 3. Then we need to identify the factors that influence certain compounds' boiling point. We'll then analyze the compounds. After that we will arrange the alcohol compounds in the proper order of their boiling points on the basis of those variables. We'll get the required answer through this.