For the following reactions where, k s and k e , are respectively, the rate constants for substitution and…

For the following reactions



where,


${\mathrm{k}}_{\mathrm{s}}$ and ${\mathrm{k}}_{\mathrm{e}}$ , are respectively, the rate constants for substitution and elimination, and $\mathrm{\mu }=\frac{{\mathrm{k}}_{\mathrm{s}}}{{\mathrm{k}}_{\mathrm{e}}}$ , the correct option is ________

1. ${\mathrm{\mu }}_{\mathrm{B}}>{\mathrm{\mu }}_{\mathrm{A}}$ and ${\mathrm{k}}_{\mathrm{e}}\left(\mathrm{A}\right)>{\mathrm{k}}_{\mathrm{e}}\left(\mathrm{B}\right)$
2. ${\mathrm{\mu }}_{\mathrm{A}}>{\mathrm{\mu }}_{\mathrm{B}}$ and ${\mathrm{k}}_{\mathrm{e}}\left(\mathrm{B}\right)>{\mathrm{k}}_{\mathrm{e}}\left(\mathrm{A}\right)$
3. ${\mathrm{\mu }}_{\mathrm{B}}>{\mathrm{\mu }}_{\mathrm{A}}$ and ${\mathrm{k}}_{\mathrm{e}}\left(\mathrm{B}\right)>{\mathrm{k}}_{\mathrm{e}}\left(\mathrm{A}\right)$
4. ${\mathrm{\mu }}_{\mathrm{A}}>{\mathrm{\mu }}_{\mathrm{B}}$ and ${\mathrm{k}}_{\mathrm{e}}\left(\mathrm{A}\right)>{\mathrm{k}}_{\mathrm{e}}\left(\mathrm{B}\right)$

Solution

(B) with more steric crowding forms elimination product compared to substitution

${\text{K}}_{\text{e}}(\text{B})>{\text{K}}_{\text{e}}(\text{A}){\mu }_{\text{B}}=\frac{{\text{K}}_{\text{s}}(\text{B})}{{\text{K}}_{\text{e}}(\text{A})}<{\mu }_{\text{A}}=\frac{{\text{K}}_{\text{s}}(\text{A})}{{\text{K}}_{\text{e}}(\text{A})}$

Asked in: JEE Main 2020 (07 Jan Shift 2)

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