Disulphide bond may be reduced to thiol by means of reagents, such as, NaBH₄, which shows the presence of thiol group in disulphide bond formation.

In the above reaction,

CH₃COOH $\stackrel{{\mathrm{SOCl}}_2}{\to }$ CH₃OCl $\underset{\mathrm{anhyd}. {\mathrm{AlCl}}_3}{\overset{\mathrm{Benzene}}{\to }}$  

Among all the given options, benzyl chloride undergoes S_N1 mechanism.

Aliphatic S_N1 reaction is carried out in two steps:

(i) carbonium (carbocation) ion is formed and its formation is based upon the stability.

Stability order of carbocation- 

C₆H₅₂$\stackrel{+}{\mathrm{C}}$H₂ > CH₃ - $\stackrel{+}{\mathrm{C}}$H - CH₃ > CH₃ - $\stackrel{+}{\mathrm{C}}$H₂

(ii) Nucleophile is attracted towards the carbonium ion in form of fast step to give final product.

Hence, in benzyl chloride, ethyl chloride and isopropyl chloride order of SN 1 reaction is benzyl chloride > isopropyl chloride > ethyl chloride

Lowest priority atom is always away from the viewer. Priority is seen on the basis of atomic number and if atomic numbers are same then on the basis of second or third bond in above figure priority order group or atom is -Br > -Cl > -CH₃ > H and in it rotation is clockwise. So it shows R-configuration. 

Correct order of acid strength is

$\underset{+1}{\mathrm{HClO}} < \underset{+3}{{\mathrm{HClO}}_2} < \underset{+5}{{\mathrm{HClO}}_3} < \underset{+7}{{\mathrm{HClO}}_4}$

Acid strength $\propto$ oxidation number

Electrolytic reduction of nitrobenzene in weakly acidic medium gives aniline but in strongly acidic medium it gives p-aminophenol through the acid-catalysed rearrangement of the initially formed phenylhydroxylamine.

   C₆H₅NO₂            $\underset{\mathrm{in} \mathrm{weakly} \mathrm{acidic} \mathrm{medium}}{\overset{\mathrm{Electrolytic} \mathrm{reduction}}{\to }}$           C₆H₅NH₂

Nitrobenzene                                                       Aniline

The main reason for larger number of oxidation states exhibited by actinides than corresponding lanthanides is lesser energy difference between 5f and 6d orbitals than between 4f and 5d-orbitals.

The major organic product formed from the above given equation is

The monomer of the above given polymer is

CH₂ = C(CH₃)₂

This is because it shows cationic polymerisation.

In the above figure, product D is C₆H₅CH₂OH.