Question

An organic compound X on heating with concentrated sulphuric acid forms a compound Y which on addition of one molecule of hydrogen in the presence of nickel forms compound Z . One molecule of compound Z on combustion forms two molecules of CO2 and three molecules of H2O . Identity giving reasons the compounds X,Y and Z..

Answer 1

Compound X forms compound Y on reaction with H2SO4. Y is undergoing addition reaction when treated with hydrogen in the presence of Nickel. So, Y is an unsaturated compound. COmpound Z undergoing combustion and forms two molecules of CO2 and 3 molecules of H2O. This hints at ethane. The reaction is:

 

 

C2H6 + 2O2 --> 2CO2 + 3H2O

 

 

So, Z os ethane. ethane is formed on hydrogenation of ethene with one molecule of hydrogen over nickel.  

 

C2H4 + H2 ------------> C2H6

 

Ethanol on dehydration with H2SO4, gives ethene

 

Compound X forms compound Y on reaction with H2SO4. Y is undergoing addition reaction when treated with hydrogen in the presence of Nickel. So, Y is an unsaturated compound. COmpound Z undergoing combustion and forms two molecules of CO2 and 3 molecules of H2O. This hints at ethane. The reaction is:

 

 

C2H6 + 2O2 --> 2CO2 + 3H2O

 

 

So, Z os ethane. ethane is formed on hydrogenation of ethene with one molecule of hydrogen over nickel.  

 

C2H4 + H2 ------------> C2H6

 

Ethanol on dehydration with H2SO4, gives ethene