Question

Part A

Which normal hydrocarbon has the highest boiling point?

Which normal hydrocarbon has the highest boiling point?

C7H16

C5H12

C6H14

Answer 1

Ans:-

n-heptane (C₇H₁₄) has highest boiling point as compare to n-hexane (C₆H₁₄) and n-pentane (C₅H₁₂). Alkanes form inter-molecular vander waal's forces and the strength of vander waal's forces increases with increase in size or mass. Since, n-heptane (C₇H₁₄) has more more size or mass therefore vander waal's forces are very much strong in n-heptane (C₇H₁₄) and hence it has highest boiling point than n-hexane and n-pentane.

The correct decreasing order of boiling point among the following given hydrocarbons is :

C₇H₁₆ > C₆H₁₄ > C₅H₁₂