Ncert Exercises & Solutions

Which is the correct increasing order of boiling points of the following compounds?

1-Iodobutane, 1-Bromobutane, 1-Chlorobutane, Butane

1.	Butane < 1-Chlorobutane < 1-Bromobutane < 1-Iodobutane
2.	1-Iodobutane < 1-Bromobutane < 1-Chlorobutane < Butane
3.	Butane < 1-Iodobutane < 1-Bromobutane < 1-Chlorobutane
4.	Butane < 1-Chlorobutane < 1-Iodobutane < 1-Bromobutane

Hint: As the surface area will increase, the intermolecular forces of attraction will also increase.

As the surface area will increase,the intermolecular forces of attraction will also increase and subsequently

bolling point will also increase. Boiling point increases with increase in molecular mass of halogen

atom for the similar type of alky! halide. Butane has no halogen atom and rest of all

three compounds are halo derivatives of butane.

‘Atomic mass of iodine is highest so the boiling point of 4-lodobutane is maximum,

among all the given compounds and hence, option (a) incorrect.