Write a short note on:
(a) Generic formula
(b) Primary, secondary, tertiary and quaternary carbon atoms.

(a) Generic formula: The general formula which represents homologous series is known as a generic formula. e.g.
Generic formula of alkane is C_nH_2n+2
Generic formula of alkene is C_nH_2n
Generic formula of alkyne is C_n H_2n_₂
(b) Primary, secondary, tertiary and quaternary carbon atoms.
(i) Primary carbon atom : It is that which is linked to one or no carbon atom. e.g. in the compound,  carbon atoms, 1 and 4 are primary carbon atoms.
(ii) Secondary carbon atom : It is that which is linked to two carbon atoms. e.g. in the compound  carbon atoms, 2 or 3 are secondary carbon atoms.
(iii) Tertiary carbon atom :  A tertiary carbon atom is linked to three carbon atoms. eg. in the compound carbon 2 is a tertiary carbon atom.


(iv) Quaternary carbon atom : A quaternary carbon atom is linked to four carbon atoms e.g. in the compound

carbon atom 2 is quaternary carbon atom.