`[P] overset(Br_(2))to C_(2)H_(4)Br_(2) underset(NH_(3))overset(NaNH_(2))to [Q] underset(Hg^(2+), Delta)overset(20% H_(2)SO_(4))to [R] overset(Zn-Hg // HCl)to [S]`
The species P, Q, R and S respectively are

Options

A. ethene, ethyne, ethanal, ethane
B. ethane, ethyne, ethanal, ethene
C. ethene, ethyne, ethanal, ethanol
D. ethyne, ethane, ethene, ethanal.

Answer

A

Explanation

`[P] overset(Br_(2))to overset(+)C_(2)H_(4)Br_(2) underset(NH_(3))overset(NaNH_(2))to Q underset(Hg^(2+), Delta)overset(20% H_(2)SO_(4))to R underset(HCl)overset(Zn-Hg)to S`
P is undergoing `Br_(2)` addition reaction and `Br_(2)` being used in 1 mol.
`:.` P is `C_(2)H_(4)` or `CH_(2)=CH_(2)`
`underset((P))(H_(2)C=CH_(2))+Br_(2) underset("Addition")overset("Anti")to underset(Br)underset(|)CH_(2)-overset(Br)overset(|)CH_(2) underset(underset("Elimination (twice)")(E_(2)))overset(overset(+)Naoverset(ddot)(barNH_(2)) // NH_(3))to underset((Q))(HC -= CH) underset(underset("Hydration reaction")(Hg^(2+), Delta))overset(20% H_(2)SO_(4))to CH_(2)=underset(OH)underset(|)CH overset("Tautomerism")harr underset((R))(CH_(3)-underset(O)underset(||)C-H) underset(Conc. HCl)overset(Zn-Hg)to underset((S))(CH_(3)CH_(3))`