(i) Vitamin-D
(ii) Cytoplasm

Amines are reactive due to the difference in electronegativity between hydrogen and nitrogen atom.

Alkaline KMnO4, acidified K₂Cr₂O₇ or HNO₃ cannot be used since all of these will cleave the molecule at the site of the double bond giving a mixture of ketones/acids. The most suitable reagent for this oxidation is NaOI (I₂/NaOH) since methyl ketones on treatment with NaOI undergo iodoform reaction to give iodoform along with the Na salt of a carboxylic acid having one carbon atom less than the starting methyl ketone
        

(a) This is because pcc is a mild oxidising agent and can oxide methanol to methanal only while KMnO₄ being strong oxidising agent oxidises it to methanoic acid.
(b) Because esterification rxn is reversible and presence of base (pyridine) neutralises HCl produced during reaction thus promoting forward reaction.

(i) \({ CH }_{ 3 }-\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CH }_{ 3 } } }{ C } } -O-{ CH }_{ 3 }+HI\longrightarrow { CH }_{ 3 }-\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CH }_{ 3 } } }{ C } } -I+\underset { Methanol }{ { CH }_{ 3 }OH } \)
(ii) \({ CH }_{ 3 }-CH={ CH }_{ 2 }\overset { (i){ B }_{ 2 }{ H }_{ 6 } }{ \underset { (ii)3{ H }_{ 2 }{ O }_{ 2 }/{ H }^{ - } }{ \longrightarrow } } { CH }_{ 3 }{ CH }_{ 2 }{ CH }_{ 2 }OH\)
 

(i) Co-enzymes : Those prosthetic groups which get attached to enzymes at the time of reaction are called co-enzymes. These increase the activity of enzymes.
(ii) Mutation in Biomolecules : A difference of a single base in DNA molecule can cause change in amino acid sequence which leads to mutation.
(iii) Nucleotides : They are monomers of nucleic acids. They consist of heterocyclic base, pentose sugar and phosphoric acis residue.

-NO₂ is a powerful dectivating group. It reduces the electron density in the benzene ring considerably. As a result, it does not undergo F.C.reactions.

\({ 3 }^{ \circ }\) amines do not react with Hinsberg's reagent.

(i) (a) Electrophilic substitution in benzoic acid takes places at meta position because carboxylic group is a deactivating group. The presence of electron withdrawing carboxylic group results in a decreased electron density at o - and p - position.
(b) Due to resonance, electrophilicity of carbonyl carbon is reduced. 
(ii) (a) Add NaOH and I₂ to both the compounds and heat them. Acetophenone forms yellow precipitate of iodoform while benzaldehyde does not.
(b) Add NaHCO₃ solution to both the compounds. Benzoic acid will give effervescence and liberate CO₂ while ethylbenzoate does not.

(i) Teacher preferred denatured alcohol over absolute alcohol as it would be unfit for drinking. As commercial alcohol is mixed with copper sulphate to give it a colour and pyridine to give a foul smell, which makes absolute alcohol unfit for drinking and called as denatured alcohol. 
(ii) As the teacher was ordering ethanol for school laboratory, maintaining discipline, repsonsible behaviour and social obligation were values kept in her mind, while taking decision.

(i) Amino acids have zwitterionic structure. Therefore. in presence of strong acids the} exist as cations' (I) and thus on electrolysis, these migrate towards cathode.
\(\overset { + }{ { NH }_{ 3 } } -CHR-{ COO }^{ - }+{ H }^{ + }\longrightarrow \quad \overset { + }{ { NH }_{ 3 } } -CHR-{ COO }H\\ \quad \quad Zwitterion\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad Cation(I)\)
In contrast, in presence of alkalies, the amino acids exist as anions (II) and thus on electrolysis, these migrate towards anode.
\(\overset { + }{ { NH }_{ 3 } } -CHR-{ COO }^{ - }+{ OH }^{ - }\longrightarrow \quad \overset { + }{ { NH }_{ 3 } } -CHR-{ COO }H\\ \quad \quad Zwitterion\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad Anion(II)\\ \)
(ii) A monoamino monocarboxylic acid such as glycine exists as a dipolar ion \((\overset { + }{ { NH }_{ 3 } } -{ CH }_{ 2 }-{ COO }^{ - })\) .In this structure, \(\overset { + }{ { NH }_{ 3 } } \) group acts as the acid and \({ COO }^{ - }\) group acts as the base. Thus, monoamino monocarboxylic acids can act both as an acid as well as a base. Therefore, these acids have two pK values one as an acid (when titrated with a base) and other as a base (when titrated with an acid).

The amide has the following resonating structures:
  
Due to the delocalisation of lone pair of electrons on N over C==O group, amino group acquires a positive charge which ma, es N-H bond weak. Moreover, the anion formed after removal of a proton is also stabilized by resonance as :
  
However, no such stabilization is possible in amines.

We know that S_N2 reactions proceed with inversion of configuration at the stereocentre. If, however, two S_N2 reactions are carried out at the same stereocentre of a compound, retention of configuration will occur. Thus, (R)-2-octanethiol can be obtained from (R)-2-bromooctane by first reacting it with Nal in acetone and then with NaSH in ethanol

C) Assertion is correct statement but reason is wrong statement.
Explanation:
For the same alkyl group, the boiling points are in the order Rl>RBr >RCl>RF. This is because with the increase in the size of halogen, the magnitude of van der Waals' force increases and boiling point increases. Bond strength decreases as the size of the halogen increases. CH3F>CH3Cl>CH3Br>CH3l and stability decreases as the strength of C-X bond decreases.

(b) Both assertion and reason are wrong statements.
Glycine is not essential amino acid because it is produced in our body, so it may not be part of our diet.

(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.

(a) In acylation reaction of amines, equilibrium shifts . to the right side in the presence of pyridine because it is a stronger base than amine which removes HCI so formed in the reaction. Thus, both (A)and (R) are correct and (R) is the correct

(c) Aromatic aldehydes are less reactive than aliphatic aldehyde like formaldehyde. Cannizzaro's reaction is shown by aldehydes which do not contain any n-H atom. Such aldehydes in the presence of concentrated solution of an alkali undergo self oxidation-reduction to give a mixture of alcohol and a salt of the carboxylic acid. For example, formaldehyde (HCHO) gives methanol and sodium methanoate.

Hence, (A) is correct but (R) is incorrect.

(a) In phenols, the - OH group is attached to sp²-hybridised carbon atom of an aromatic ring. As a result, a partial double bond exist between c-obond. So, the carbon oxygen bond length (136 pm) in phenol is slightly less than that in methanol. Hence, both (A) and (R) are correct and R is the correct explanation of (A).