Hydrocarbons - Result Question 13

13. The highest boiling point is expected for

(1986,1 M)

(a) iso-butane

(b) $n$-octane

(c) $2, 2, 3, 3$-tetramethyl butane

(d) $n$-butane

Show Answer

Answer:

Correct Answer: 13. (b)

Solution:

  1. Boiling point of alkane increases with molar mass. Among isomeric alkanes, branching decreases boiling point. Therefore, $n$-octane has highest boiling point, higher than $2, 2, 3, 3$-tetramethyl-butane (an isomer of $n$-octane).