Ethers like ROR can be cleaved by concentrated HI but not by HCl because

• I^- is a weaker nucleophile than Cl^-

• I^- is stronger nucleophile than Cl^-

• S_N1 mechanism carried out in this reaction is rapidly in presence of HI.

• None of the above

Consider the following reaction sequence

CH₃OH $\stackrel{\mathrm{HBr}}{\to }$ 'A' $\stackrel{KCN}{\to }$ 'B' $\stackrel{{\mathrm{H}}_2/ \mathrm{Ni}}{\to }$ 'C' $\stackrel{{\mathrm{HNO}}_2}{\to }$ 'D'

Choose the correct option regarding the different products obtained in the above reaction sequence:

• 'D' is an alcohol consisting one carbon more than the starting alcohol

• Product 'B' is formed via S_N2-pathway

• 'C' is an amine

• All of the above

683.

The relative reactivities of acyl compounds towards nucleophilic substitution are in the order of

• acyl chloride > acid anhydride > ester > amide

• ester > acyl chloride > amide > acid anhydride

• acid anhydride > amide > ester > acyl chloride

• acyl chloride> ester> acid anhydride > amide

The suitable reaction steps to carry out the following transformation is

• $\underset{\left(\mathrm{ii}\right) {\mathrm{H}}_2{\mathrm{O}}_2, \mathrm{NaOH}}{\overset{\left(\mathrm{i}\right) {\mathrm{BH}}_3, \mathrm{THF}}{\to }} \stackrel{{\mathrm{HIO}}_4}{\to }$

• $\underset{({\mathrm{CH}}_3{)}_3\mathrm{C}.\mathrm{COOH}, {\mathrm{OH}}^{-}}{\overset{{\mathrm{OsO}}_4}{\to }} \underset{{\mathrm{H}}_2\mathrm{O}}{\overset{{\mathrm{K}}_3{\mathrm{Cr}}_2{\mathrm{O}}_7.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}$

• $\underset{\left(\mathrm{ii}\right) {\mathrm{H}}_2{\mathrm{O}}_2, \mathrm{NaOH}}{\overset{\left(\mathrm{i}\right) {\mathrm{BH}}_3, \mathrm{THF}}{\to }} \underset{{\mathrm{CH}}_2{\mathrm{Cl}}_2}{\overset{\mathrm{PCC}}{\to }}$

• $\stackrel{{\mathrm{H}}_2\mathrm{O}, {\mathrm{H}}_2{\mathrm{SO}}_4 \left(\mathrm{dil}\right)}{\to } \underset{{\mathrm{CH}}_2{\mathrm{Cl}}_2}{\overset{\mathrm{PCC}}{\to }}$

The major product P will be

The product P of the given reaction is 

In the reaction 

C₇H₈ $\stackrel{3{\mathrm{Cl}}_2/ ∆}{\to }$ X $\stackrel{{\mathrm{Br}}_2/ \mathrm{Fe}}{\to }$ Y $\stackrel{\mathrm{Zn}/ \mathrm{HCl}}{\to }$ Z

Z is

• o-bromotoluene

• m-bromotoluene

• p-bromotoluene

• 3-bromo-2, 2, 6- trichlorotoluene

The molal freezing point depression constant for benzene (C₆H₆) is 4.90 K Kg mol^-1. Selenium exists as a polymer of the type Se_x. When 3.26 g of selenium is dissolved in 226 g of benzene, the observed freezing point is 0.112$°$C lower than that of pure benzene. The molecular formula of selenium is (atomic mass of Se = 78.8 g mol^-1).

• Se₈

• Se₆

• Se₄

• Se₂

X, Y and Z respectively are

Choose the correct alkyne and reagents for the preparation of