question_answer 1)

Arrange the following in decreasing order of their boiling points : (A) n-butane                                                                      (B) 2-methylbutane (C) n-pentane                                                                   (D) 2, 2-dimethylpropane (a) \[A>B>C>D~\]            (b)\[B>C>D>A\]               (c)\[~D\text{ }>\text{ }C\text{ }>\text{ }B\text{ }>\text{ }A\]                (d) \[C\text{ }>\text{ }B\text{ }>\text{ }D\text{ }>\text{ }A\]

Answer:

(d) Boiling points decrease with increase in branching and decrease in total number of carbon atoms.