Question

Which one of the following has a high boiling point? [ also explain with reason ] a. propan-1-ol b) butan-2-ol c) butan-1-ol d) 2-methyl propan-2-ol

Answer 1

Explanation:

Which one of the following has a high boiling point?

a) propan-1-ol

b) butan-2-ol

c) butan-1-ol ✔

d) 2-methyl propan-2-ol

Reason :-

The boiling point of alcohol increase with the increase in number of C-atoms (due to increase in van der waals' forces). In Alcohol, the boiling point decrease with increase of branching in C-chain. (due to decrease of van der waals' force with decrease in surface area).

➳ In propanol and 2-methyl propan-2-ol , it's 3-C chain and there is a branching in 2-methyl propan-2-ol.

And

➳ In butan-2-ol and butan-1-ol it's 4 C-Chain and there is branching in butan-2-ol. So, BP decrease in butan-2-ol.

Hence,

butan-1-ol has higher boiling point (BP).

Additional information :-

Physical state :-

• At room temperature, lower alcohols are colourless liquids with distinct smell and burning taste.
• The higher member are colourless, odourless, waxy solid.

Boiling point :-

• The boiling point of alcohol and phenols increase with increase in number of C-atoms.

Reason -

Due to increase in van der waals' force.

Solubility :-

• The solubility of alcohols and phenols in water is due to their ability to form H-bonds with water molecules