CBSE Class 10 Sample Paper Science Solution - For 2023 Boards

Shristi heated Ethanol with a compound A in presence of a few drops of concentrated sulphuric acid and observed a sweet smelling compound B is formed.

When B is treated with sodium hydroxide it gives back Ethanol and a compound C.

  1. Identify A and C
  2. Give one use each of compounds A and B.
  3. Write the chemical reactions involved and name the reactions.




  • The sweet smelling compound is ester obtained on reaction of Carboxyllic acids (except methanoic acid) with conc. H2SO4 .
  • Therefore,  

A - Ethanoic acid / Or any other carboxylic acid 

B - Ester 

C - Sodium salt of ethanoic acid/ any other carboxylic acid/ sodium ethanoate 

(b) A- used as dil solution used as vinegar in cooking/ preservative in pickles

B – used in making perfumes, as flavoring agent  


Esterification Reaction:

CH 3 COOH + C 2 H 5 OH------------> CH 3 COOC 2 H 5 +H 2

Saponification Reaction:

CH 3 COOC 2 H 5 + NaOH----------> CH 3 COONa + C 2 H 5 OH

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CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo