(A) (i) Define a homologous series of carbon compounds. (ii) Why is the melting and boiling points of C 4 H…
(A) (i) Define a homologous series of carbon compounds.
(ii) Why is the melting and boiling points of C4H8 higher than that of C3H6 or C2H4 ?
(iii) Why do we NOT see any gradation in chemical properties of a homologous series compounds ?
(iv) Write the name and structures of (i) aldehyde and (ii) ketone with molecular form C3H6O.
Solution
(A)
(i) A series of carbon compounds in which the same functional group substitutes for hydrogen in a carbon chain / Series of compounds having same functional group and similar chemical properties.
(ii) Because melting point and boiling point increase with molecular mass.
(iii) Because chemical properties of organic compounds are solely determined by their functional group which remains same in a homologous series.
(iv) (i) Aldehyde: Propanal
[structural formula: H3C-CH(H)-C(=O)-H] / CH3CH2CHO
(ii) Ketone: Propanone
[structural formula: H3C-C(=O)-CH3] / CH3COCH3