An organic compound A on heating with concentrated `H_(2)SO_(4)` forms a compound B which on addition of one mole of hydrogen in presence of Ni forms a compounds C. One mole od compound C on combustion form two moles of `CO_(2)` and three moles of `H_(2)O`. Identify the compounds A,B and C write the chemical equation of the reactions involved.

Explanation

Combustion of compound C forms two moles of `CO_(2)` and three moles of `H_(2)O` so it must contain two carbon atoms and six hydrogen atoms with molecular formula `C_(2)H_(6)` that is ethene.
Ethane is formed by the addition of one mole of hydrogen in the presence of Ni catalyst on compound B. So compound B must be unsaturated hydrocarbon with two carbon atoms that is ethene `(CH_(2)=CH_(2))`.
`underset((A))(C_(2)H_(5)OH)overset("Hot conc"H_(2)SO_(4))tounderset((B))(C_(2)H_(4))+H_(2)O`
`underset((B))(C_(2)H_(4))+H_(2)overset(Ni)tounderset((C))(C_(2)H_(6))`
`underset((C))(2C_(2)H_(6))+7O_(2)to4CO_(2)+6H_(2)O+`Heat and light
Hence , A = Ethanol `(CH_(3)CH_(2)OH),B`= Ethene `(CH_(2)=CH_(2))andC="Ethane"(CH_(3)=CH_(3))`