Question

Consider the following statements about homologous series of carbon compounds:
(a) All succeeding members differ by –CH2 unit.
(b) Melting point and boiling point increases with increasing molecular mass.
(c) The difference in molecular masses between two successive members is 16 u.
(d) C2H2 and C3H4 are NOT the successive members of alkyne series.
The correct statements are –

• A. (a) and (b)
• B. (b) and (c)
• C. (a) and (c)
• D. (c) and (d)

Answer 1

Answer: (A)

(a) and (b)

Answer 2

• (a) is correct because members of a homologous series differ by a $CH_2$ unit.
• (b) is correct as the melting and boiling points increase with increasing molecular mass due to stronger van der Waals forces.
• (c) is incorrect because the difference in molecular mass between two successive members is 14 u, not 16 u.
• (d) is incorrect as $C_2H_2$ and $C_2H_4$ belong to different series (alkyne and alkene, respectively).