\(\mathrm{R}-\mathrm{NH}_{2}\) (Amines) behaves as a Lewis base because it is capable of donating a lone pair of electrons.
KCET - 2008
CHXII13:AMINES
324077
Statement A : Acetanilide is less basic than aniline. Statement B : Acetylation of aniline results in decrease of electron density on nitrogen.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
Conceptual Questions
CHXII13:AMINES
324078
Assertion : Aniline is a weaker base than ethylamine. Reason : Lower the value of \(\mathrm{pK}_{\mathrm{b}}\) stronger is the base.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
The lone pair of electrons on the nitrogen \((\mathrm{N})\) atom in aniline is delocalized over the benzene ring, and this delocalization reduces its availability for protonation. This makes aniline a weaker base than ethylamine, which does not have such extensive electron delocalization. Reason is also true. So the option (2) is correct.
CHXII13:AMINES
324079
Which of the following amines is most basic in nature in aqueous phase?
1 Methylamine
2 Trimethylamine
3 Dimethylamine
4 Ammonia
Explanation:
Dimethylamine is most basic in nature in aqueous phase. It is more basic as, it is a secondary amine. The lone pair of electrons on the nitrogen atom is further away from the nucleus at a higher energy level due to extra repulsion from the electrons in each \(\mathrm{C}-\mathrm{N}\) bond, thus the nitrogen atom is more capable at donating a pair of electrons. So, dimethylamine is a strong base in solution (aqueous phase), as more \(\mathrm{OH}^{-}\)ions are formed, when nitrogen atom accepts a proton causing the solution to be more alkaline as the \(\mathrm{pH}\) higher. \(\mathrm{CH}_{3} \mathrm{NHCH}_{3}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{CH}_{3} \mathrm{NH}_{2} \mathrm{CH}_{3}+\mathrm{OH}^{-}\)
\(\mathrm{R}-\mathrm{NH}_{2}\) (Amines) behaves as a Lewis base because it is capable of donating a lone pair of electrons.
KCET - 2008
CHXII13:AMINES
324077
Statement A : Acetanilide is less basic than aniline. Statement B : Acetylation of aniline results in decrease of electron density on nitrogen.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
Conceptual Questions
CHXII13:AMINES
324078
Assertion : Aniline is a weaker base than ethylamine. Reason : Lower the value of \(\mathrm{pK}_{\mathrm{b}}\) stronger is the base.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
The lone pair of electrons on the nitrogen \((\mathrm{N})\) atom in aniline is delocalized over the benzene ring, and this delocalization reduces its availability for protonation. This makes aniline a weaker base than ethylamine, which does not have such extensive electron delocalization. Reason is also true. So the option (2) is correct.
CHXII13:AMINES
324079
Which of the following amines is most basic in nature in aqueous phase?
1 Methylamine
2 Trimethylamine
3 Dimethylamine
4 Ammonia
Explanation:
Dimethylamine is most basic in nature in aqueous phase. It is more basic as, it is a secondary amine. The lone pair of electrons on the nitrogen atom is further away from the nucleus at a higher energy level due to extra repulsion from the electrons in each \(\mathrm{C}-\mathrm{N}\) bond, thus the nitrogen atom is more capable at donating a pair of electrons. So, dimethylamine is a strong base in solution (aqueous phase), as more \(\mathrm{OH}^{-}\)ions are formed, when nitrogen atom accepts a proton causing the solution to be more alkaline as the \(\mathrm{pH}\) higher. \(\mathrm{CH}_{3} \mathrm{NHCH}_{3}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{CH}_{3} \mathrm{NH}_{2} \mathrm{CH}_{3}+\mathrm{OH}^{-}\)
\(\mathrm{R}-\mathrm{NH}_{2}\) (Amines) behaves as a Lewis base because it is capable of donating a lone pair of electrons.
KCET - 2008
CHXII13:AMINES
324077
Statement A : Acetanilide is less basic than aniline. Statement B : Acetylation of aniline results in decrease of electron density on nitrogen.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
Conceptual Questions
CHXII13:AMINES
324078
Assertion : Aniline is a weaker base than ethylamine. Reason : Lower the value of \(\mathrm{pK}_{\mathrm{b}}\) stronger is the base.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
The lone pair of electrons on the nitrogen \((\mathrm{N})\) atom in aniline is delocalized over the benzene ring, and this delocalization reduces its availability for protonation. This makes aniline a weaker base than ethylamine, which does not have such extensive electron delocalization. Reason is also true. So the option (2) is correct.
CHXII13:AMINES
324079
Which of the following amines is most basic in nature in aqueous phase?
1 Methylamine
2 Trimethylamine
3 Dimethylamine
4 Ammonia
Explanation:
Dimethylamine is most basic in nature in aqueous phase. It is more basic as, it is a secondary amine. The lone pair of electrons on the nitrogen atom is further away from the nucleus at a higher energy level due to extra repulsion from the electrons in each \(\mathrm{C}-\mathrm{N}\) bond, thus the nitrogen atom is more capable at donating a pair of electrons. So, dimethylamine is a strong base in solution (aqueous phase), as more \(\mathrm{OH}^{-}\)ions are formed, when nitrogen atom accepts a proton causing the solution to be more alkaline as the \(\mathrm{pH}\) higher. \(\mathrm{CH}_{3} \mathrm{NHCH}_{3}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{CH}_{3} \mathrm{NH}_{2} \mathrm{CH}_{3}+\mathrm{OH}^{-}\)
\(\mathrm{R}-\mathrm{NH}_{2}\) (Amines) behaves as a Lewis base because it is capable of donating a lone pair of electrons.
KCET - 2008
CHXII13:AMINES
324077
Statement A : Acetanilide is less basic than aniline. Statement B : Acetylation of aniline results in decrease of electron density on nitrogen.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
Conceptual Questions
CHXII13:AMINES
324078
Assertion : Aniline is a weaker base than ethylamine. Reason : Lower the value of \(\mathrm{pK}_{\mathrm{b}}\) stronger is the base.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
The lone pair of electrons on the nitrogen \((\mathrm{N})\) atom in aniline is delocalized over the benzene ring, and this delocalization reduces its availability for protonation. This makes aniline a weaker base than ethylamine, which does not have such extensive electron delocalization. Reason is also true. So the option (2) is correct.
CHXII13:AMINES
324079
Which of the following amines is most basic in nature in aqueous phase?
1 Methylamine
2 Trimethylamine
3 Dimethylamine
4 Ammonia
Explanation:
Dimethylamine is most basic in nature in aqueous phase. It is more basic as, it is a secondary amine. The lone pair of electrons on the nitrogen atom is further away from the nucleus at a higher energy level due to extra repulsion from the electrons in each \(\mathrm{C}-\mathrm{N}\) bond, thus the nitrogen atom is more capable at donating a pair of electrons. So, dimethylamine is a strong base in solution (aqueous phase), as more \(\mathrm{OH}^{-}\)ions are formed, when nitrogen atom accepts a proton causing the solution to be more alkaline as the \(\mathrm{pH}\) higher. \(\mathrm{CH}_{3} \mathrm{NHCH}_{3}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{CH}_{3} \mathrm{NH}_{2} \mathrm{CH}_{3}+\mathrm{OH}^{-}\)
