Question

The molecules of alkene family are represented by a general formula C_nH_2n.
Answer the following:
(i) What do n and 2n signify?
(ii) What is the name of alkene when n=4?
(iii) What is the molecular formula of the alkene, if there are six
hydrogen atoms in it?
(iv) Write the molecular and structural formula of the first member of
alkene family.
(v) Write the molecular formulae of lower and higher homologues of
an alkene which contains four carbon atoms.

Answer 1

(i) The n signifies Number of carbon atoms where as 2n signifies Number of Hydrogen atoms.

(ii) Butene

(iii) Molecuar Formula of first member of alkene is: C₂H₄

Structural formula:

(v) Lower Homologues of alkene which contains four carbon atoms is : C₃H₆

Higher homologues of alkene which contains four carbon atoms is : C₅H₁₀