Arrange the following compounds in increasing order of their boiling points.

(i)       

(ii) CH3CH2CH2CH2Br

(iii)

1.  (ii) < (i) < (iii) 

2.  (i) <(ii) <(iii) 

3.  (iii) <(i) <(ii) 

4.  (iii) < (ii) <(i) 

Surface area is main determining factor for boiling point of compound. As we increase the surface area, the bolling point of a compound will also increase. Consequently As we increase number of branching, surface area will decrease. If the compound has branching in it's structure then its bolling point will be minimum,

Thus, the increasing order of their boiling points

 <  < CH3CH2CH2CH2Br