Question

A  carbon  compound  ‘A’  having  melting  point  156K  and  boiling  point  351K, with molecular  formula  C₂H₆O is soluble in water in all proportions. 

(a) Identify  ‘A’  and draw its electron dot structure. 

(b) Give the molecular formulae of any  two homologues of ‘A’ .

Answer 1

a. Ethanol; C₂ H₅ OH

Ethanol is a colourless liquid having boiling point 351k and melting point 156k

Also it is soluble in water

Its formula is C₂ H₅ OH

Electron Dot Structure of Ethanol is as follows

(b) Ethanol is an alcohol

Examples of Alcohols

Methanol	CH3 OH
Ethanol	C2 H5 OH
Propanol	C3 H7 OH
Butanol	C4 H9 OH

Note:

All the above are homologues

Homologues are group of chemical compounds which have similar structure and similar chemical properties and successive compounds differ by CH₂

We can say that homologues of ethanol are

Methanol	CH3 OH
Propanol	C3 H7 OH

Answer 2

a. Ethanol; C₂H₅OH

b. CH₃OH and C₃H₇OH are homologues of ethanol

OR

CH₄O and C₃H₈O