The formulae of four organic compounds are given below: (i) Which one of these compounds A, B, C or D is a saturated hydrocarbon?

Question

The formulae of four organic compounds are given below: 

A	B	C	D
C2H4	CH3COOH	C2H5OH	C2H6

(i) Which one of these compounds A, B, C or D is a saturated hydrocarbon? 

(ii) Identify the organic acid and give its structural formula. 

(iii) Which of the above compounds when heated at 443K in the presence of concentrated H₂SO₄ forms ethene as the major product? What is the role played by concentrated H₂SO₄ in this reaction? Also write the chemical equation involved. 

(iv) Give a chemical equation when B and C react with each other in presence of concentrated H₂SO₄. Name the major product formed and mention one of its important use. 

Answer 1

(i) Saturated hydrocarbons are the one which has only single bond with in the carbon atoms.

Compound D which is ethane is a saturated hydrocarbon.

(ii) Compound B which is ethanoic acid is an organic acid as it has carboxylic acid group -COOH.

The structural formula is:

(iii) Compound C which is ethanol. On heating, it gives ethene as the major product. The reaction is shown below as:

\(C_2H_5OH \xrightarrow[H_2SO_4]{Heat} C_2 H_4 + H_2 O\)

H₂SO₄ acts as a dehydrating agent which eliminates water from ethanol. It acts as catalyst.

(iv) On reacting compound B and C, ethanoic acid and ethanol, it give ester, ethyl ethanoate. They are sweet smelling compounds and used as artificial flavoring agents.

Answer 2

(i) D is a saturated hydrocarbon 

(ii) B is an organic acid. 

Structural formula

(iii) C is the compound. 

It acts as a dehydrating agent and removes a water molecule from ethanol.

(iv)

Major product is Ester and it is used in making perfumes / flavouring agents.