Question

(a) Give the names and structural formulae of the next two higher homologues of methane.
(b) The molecular formula of a hydrocarbon is C₁₀H₁₈. Name its homologous series.
(c) Select the hydrocarbons which are members of the same homologous series. Give the name of each series.
C₅H₁₀; C₃H₈; C₆H₁₀; C₄H₁₀; C₇H₁₂; C₈H₁₆

Answer 1

(a) Ethane (C₂H₆) and propane (C₃H₈) are the names of the successive homologues of methane.
Their structural formulae are as follows:


(b) The homologous series of a hydrocarbon with the molecular formula C₁₀H₁₈ is alkynes (C_nH_2n-2).

(c)
(i) C₃H₈ and​ C₄H₁₀ are the hydrocarbons belonging to the homologous series of alkanes.
(ii) C₅H₁₀ and​ C₈H₁₆ are the hydrocarbons belonging to the homologous series of alkenes.
(iii) C₆H₁₀ and​ C₇H₁₂ are the hydrocarbons belonging to the homologous series of alkynes.