question_answer

Which one of the following graphs represent the correct order of boiling points (b. p.) of ethane (1), ethyl alcohol (2) and acetic acid (3)?

A)                                                

B)

C)                                                                

D)

Correct Answer: C

Solution :

                  In both ethyl alcohol (2) and acetic acid (3) hydrogen bonding is present and the extent of H-bonding is more in acetic acid than ethyl alcohol due to formation of ring. Thus, acetic acid has higher b. p. than ethyl alcohol. Ethane (1) has lowest boiling point  due   to   absence   of B.P H-bonding.  Hence,  the graph  showing  correct order of boiling points is