Chemistry M.C.Q (1 Marks)

Diphenyl hydrazine is same as hydrazobenzene.
Two phenyl groups are attached to two nitrogen atoms of hydrazine.

By the presence of a halogen atom in the ring, basic properties of aniline is increased because it is more electronegative so donation of electron will be easy, so basicity increases.

Benzyl amine is more basic than anniline.
while ethyl amine is less basic than diethyl amine.

Gabriel synthesis is used for the preparation of primary amines. Phthalimide on treatment with ethanolic potassium hydroxide forms potassium salt of phthalimide which on heating with alkyl halide followed by alkaline hydrolysis produces the corresponding primary amine. Aromatic primary amines cannot be prepared by this method because aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide.

The structure of given amines are as follows:

Hoffmann developed a method for preparation of primary amines by treating an amide with bromine in an aqueous or ethanolic solution of sodium hydroxide. In this degradation reaction, migration of an alkyl or aryl group takes place from carbonyl carbon of the amide to the nitrogen atom.

Phenol react with aniline to give diazonium salt by coupling but Methyl amine not react with phenolss.

The diazonium salts are the reaction product in presence of excess of mineral acid with nitrous acid and primary aromatic amine.

Basic strength depends upon the electron donating capacity of the central atom, here amide is most basic due to presence of negative charge and two lone pair of electrons on nitrogen atom.

Gabriel phthalamide cannot be used to prepare aromatic amines since aromatic halides donot undergo nucleophilic subsitution from the salt formed by phthalamide.

is named Gatterman reaction.

Electron withdrawing group decreases the basic strength while electron releasing groups increases the basic strength of aniline.

some experiments describe on calcium and barium azid and tetrazene, which explode while they are solid.
The explosion of the molten azides is due to self heating of the liquid.
Explosion is facilitated by the presence of an inert gas above the decomposing liquid self heating of the liquid azides is due to the retention of heat products of reaction near the surface.

Nitrobenzene is reduced to phenylammonium ions using a mixture of tin and concentrated hydrochloric acid.
The mixture is heated under reflux in a boiling water bath for about half an hour.
Under the acidic conditions, rather than getting phenylamine directly, you instead get phenylammonium ions formed.

Four primary amines are possible for this structure.

Amines are basic compound.
They are colourless but develop colour on keeping in the air for a long time because they react readily air and get oxidised.

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Explanation:
Phenol is the weakest Bronsted base as it is the strongest acid among the four choices given above. Stronger the acid weaker is its conjugate base.

Here carbylamine is given secondary amine.

Methyl amine is the strongest base.

In aqueous solution tertiary amines are unexpectedly less basic than the others.
This is due to steric factor and solvation of ions.

Amino acid present only in bacteria and cyanobacteria is diaminopimellic acid.
The amino acid only in bacteria and blue algea are methaionine, diaminopimellic, aspartic acid, glutamic acid.

Primary and secondary amines can form hydrogen bonds whereas tertiary amines fail to do so. Hence, their boiling points are lowest.

Acid anhydride on reaction with primary amine produces amide as:

Primary aliphatic amines react with nitrous acid to form aliphatic diazonium salts which being unstable, liberate nitrogen gas quantitatively and alcohol.

Since the compound consists of a benzene ring, it invariably is an aromatic amine. Moreover, it also contains an alkyl methyl group beside the phenyl group and this makes it a mixed amine.

In the given amine, there are two substituents, one methyl group and one phenyl group.
Hence, it is a secondary aryl amine and since both the substituent groups are different, it is a mixed amine.

Gabriel phthalimide synthesis is used for the preparation of aliphatic primary amines. Since ethanamine is the only primary amine among the given compounds,

Ethylamine possesses two hydrogen atoms that can form hydrogen bonds wheras diethylamine having only one hydrogen atom is capable of forming only one hydrogen bond.

Amines are derivatives of ammonia.
If one hydrogen of ammonia is replaced by an alkyl group, it is called a primary amine.
If two hydrogens of ammonia are replaced by alkyl groups, it is called a secondary amine.
If three hydrogens of ammonia are replaced by alkyl groups, it is called a tertiary amine.
So, tertiary, secondary, and primary amine represents the degree of substitution on the nitrogen.

Explanation: b. IV.
1° and 2° amines have higher boiling points due to intermolecular H-bonding (and hence less volatile than 3° amines and hydrocarbons of comparable molecular mass).

Nitro compounds are reduced to amines by passing hydrogen gas in the presence of finely divided nickel, palladium or platinum and also by reduction with metals in acidic medium.