When ethanol is heated at `170^(@)C` with conc. `H_(2)SO_(4)`, it forms an organic compound 'A' and water. The compound 'A' reacts with hydrogen in the presence of nickel to form 'B'.
i. Name the compounds A and B. Write the chemical equations of the reactions involved.

Explanation

Compound A is ethene `(CH_(2)=CH_(2))`.
Compound B is ethane `(CH_(3)-CH_(3))`.
Reactions :
`underset("Ethanol")(CH_(3)-CH_(2)-OH)overset("Conc. "H_(2)SO_(4))underset(170^(@)C)rarr underset("(A)") underset("Ethene")(CH_(2)=CH_(2))+underset("Water")(H_(2)O)`
`underset("(A)")underset("Ethene")(CH_(2)=CH_(2))overset(H_(2))underset("nickel")rarr underset("(B)")underset("Ethane")(CH_(3)-CH_(3))`