Question

Which of the following is the least volatile?
(A) $ C{H_3} - C{H_2} - C{H_2} - F $
(B) $ C{H_3} - C{H_2} - C{H_2} - Cl $
(C) $ C{H_3} - CH\left( {Br} \right) - C{H_3} $
(D) $ C{H_3} - C{H_2} - C{H_2} - Br $

Answer 1

Hint: This question gives the knowledge about the volatile liquids. Volatile liquids get vaporized very readily. Volatile liquids experience very low boiling point. Boiling point is considered as the main element for determining the volatility.

Complete step by step answer
Volatile liquids get vaporized very readily. Volatile liquids experience very low boiling point. Boiling point is considered as the main element for determining the volatility. The volatility rate decreases and the boiling point increases as the Vander Waals interaction between the molecules or atoms increases. The Vander Waals interaction generally depends upon the size or the surface area of a molecule. Very less amount of energy is required to break down the intermolecular bonds present in volatile liquids. The important examples of volatile liquids are acetone, diethyl ether, dichloromethane and so forth.
On considering the chains of alkyl halides, we observe the increase in the boiling point of halides because on moving down the group in periodic table the boiling points of the elements generally increases. The branching in the isomers of the same compounds leads to decrease in the boiling points of chemical compounds. So, $ C{H_3} - C{H_2} - C{H_2} - Br $ will experience the highest boiling point. As we know, boiling point is inversely proportional to the volatility rate of liquids. Therefore, $ C{H_3} - C{H_2} - C{H_2} - Br $ is least volatile.
Hence, option $ D $ is the correct option.

Note
Always remember that the volatile liquids get vaporized very readily. Volatile liquids experience very low boiling point. Boiling point is considered as the main element for determining the volatility. Very less amount of energy is required to break down the intermolecular bonds present in volatile liquids.