289. Arrange the following in order of increasing boiling points:

Alcohol have ability to form hydrogen bond therefore it forms bond with hydrogen and thus strengthen the bond. thus, boiling point of alcohol is more then haloalkane.
Since molecule (iii) has two hydroxy group therefore it forms more stronger hydrogen bond than (iv). In case of haloalkane bromine is larger in size thus vander waal forces is more as campare to chlorine thus order of increasing boiling point is given in order;