91影视

In part (a), in nicotine, the pyridine ring鈥檚 nitrogen atom which is marked 鈥淎鈥� is
${\mathrm{sp}}^2$hybridised and other nitrogen atom which is marked 鈥淏鈥� which is a part of five-membered ring is tertiary aliphatic in nature and is ${\mathrm{sp}}^3$hybridised. Since, ${\text{sp}}^3$nitrogen is more basic than ${\mathrm{sp}}^2$hybridised nitrogen and this is due to fact that, closeness of electrons of atom increases towards the nucleus when s-character increases and thereby hold of electrons by nucleus increases due to which the lone pair donation becomes difficult and basicity decreases. Thus, basicity of B is more than A.

The lone pair present on nitrogen atom makes the nitrogen in amines electron dense. Greater the lone pair availability on nitrogen atom to donate to other species, more will be its basicity. Basicity of nitrogen atom will decrease if lone pair is not available for donation to other species as in case of aromatic species, the lone pair is delocalised in the ring and not available for donation to other species. Amides are less basic than amines due to delocalisation of the lone pair of nitrogen towards the carbonyl group present adjacent to it.

In part (b), nitrogen atom which is marked 鈥淐鈥� is more basic than nitrogen atom which is marked 鈥淒鈥�, as amides are less basic than amines due to non-availability of lone pair of nitrogen as lone pair of nitrogen in amide is in delocalisation with carbonyl group adjacent to it.

The lone pair present on nitrogen atom makes the nitrogen in amines electron dense. Greater the lone pair availability on nitrogen atom to donate to other species, more will be its basicity. Basicity of nitrogen atom will decrease if lone pair is not available for donation to other species as in case of aromatic species, the lone pair is delocalised in the ring and not available for donation to other species. Amides are less basic than amines due to delocalisation of the lone pair of nitrogen towards the carbonyl group present adjacent to it.

In part (c), nitrogen atom which is marked 鈥淔鈥� is more basic than the nitrogen atoms which are marked 鈥淓鈥� and 鈥淕鈥�. As, 鈥淔鈥� nitrogen atom is tertiary aliphatic amine whereas, 鈥淓鈥� nitrogen atom is aromatic and 鈥淕鈥� nitrogen atom is hybridised, so its basicity will be least among all three as hold of lone pair of electrons of nitrogen atom will be strongest towards nucleus due to more s-character so electron donation availability decreases. 鈥淓鈥� nitrogen atom is less basic as the lone pairs are involved in delocaisation with the rings.

The lone pair present on nitrogen atom makes the nitrogen in amines electron dense. Greater the lone pair availability on nitrogen atom to donate to other species, more will be its basicity. Basicity of nitrogen atom will decrease if lone pair is not available for donation to other species as in case of aromatic species, the lone pair is delocalised in the ring and not available for donation to other species. Amides are less basic than amines due to delocalisation of the lone pair of nitrogen towards the carbonyl group present adjacent to it.

In part (d), 鈥淚鈥� marked nitrogen atom has more basicity than 鈥淗鈥� marked nitrogen atom as 鈥淚鈥� nitrogen atom is tertiary aliphatic amine whereas 鈥淗鈥� nitrogen atom is aromatic and its lone pairs are involved in delocalisation with the ring.

The lone pair present on nitrogen atom makes the nitrogen in amines electron dense. Greater the lone pair availability on nitrogen atom to donate to other species, more will be its basicity. Basicity of nitrogen atom will decrease if lone pair is not available for donation to other species as in case of aromatic species, the lone pair is delocalised in the ring and not available for donation to other species. Amides are less basic than amines due to delocalisation of the lone pair of nitrogen towards the carbonyl group present adjacent to it.

In part (e), nitrogen atom marked 鈥淟鈥� have higher basicity than nitrogen atom marked 鈥淛鈥� and 鈥淜鈥�. Nitrogen atom 鈥淟鈥� is secondary aliphatic amine whereas 鈥淜鈥� nitrogen atom is amide and 鈥淛鈥� nitrogen atom is aromatic. Amides are least basic and aromatic nitrogen is less basic than secondary amine nitrogen due to involvement of lone pairs of nitrogen in ring and thus lone pairs are not available for donation in nitrogen atom 鈥淛鈥�.

The lone pair present on nitrogen atom makes the nitrogen in amines electron dense. Greater the lone pair availability on nitrogen atom to donate to other species, more will be its basicity. Basicity of nitrogen atom will decrease if lone pair is not available for donation to other species as in case of aromatic species, the lone pair is delocalised in the ring and not available for donation to other species. Amides are less basic than amines due to delocalisation of the lone pair of nitrogen towards the carbonyl group present adjacent to it.

In part (f), Nitrogen atom marked 鈥淣鈥� is more basic than nitrogen atom marked 鈥淢鈥� and 鈥淥鈥�. Nitrogen atom 鈥淣鈥� is tertiary aliphatic amine and thus is most basic whereas 鈥淢鈥� nitrogen atom is less basic as it is aromatic and its lone pairs are involved in the ring in delocalisation. Nitrogen atom 鈥淥鈥� is amide and its lone pairs are not available for donation to other species as they are involved in delocalisation with carbonyl group adjacent to it, thus are least basic.