Question

Compound A is used as a solvent in cough syrup.
a) write the equation for the combustion of A.
b) when A is heated with concentration sulphuric acid water is removed and gas B is formed.
c) write the electron dot structure of B.
d) name the type of reaction B undergoes with hydrogen.

Answer 1

Explanation:

a) Compound A which serves as a solvent in a cough syrup is an ethanol.

Compound A = $C_2H_5OH$

$C_2H_5OH+3O_2\rightarrow 2CO_2+3H_2O$

b) When we heat the ethanol in presence of sulfuric acid dehydration occurs in which water molecule is removed and unsaturated hydrocarbon i.e. ethene gas is produced.

$C_2H_5OH+H_2SO_4\rightarrow CH_2=CH_2$

Compound B = Ethene =$C_2H_4$

c) The electron dot structure of B is given in an image.

d) Ethene with hydrogen gas undergoes addition reaction in which hydrgen atom gets added to ethene molecule to give saturated hydrocarbon that is ethane.This type of reaction is termed a Hydrogenation.

$CH_2=CH_2+H_2\rightarrow C_2H_6$