1. ⇒ (MHT CET 2023 12th May Evening Shift )

Which of the following compounds does NOT develop intermolecular hydrogen bonding?

A. Cyclohexylamine

B. Allylamine

C. Trimethylamine

D. Diphenylamine

Correct Option is (C)

Trimethylamine, $N ({CH}_{3})$ does not contain $N - H$ bond and hence it does not develop intermolecular hydrogen bonding.

2. ⇒ (MHT CET 2023 11th May Morning Shift )

Which among the following amines has highest value of ${pK}_{b}$ ?

A. ${({CH}_{3})}_{2} NH$

B. ${({CH}_{3})}_{3} N$

C. ${CH}_{3} {NH}_{2}$

D. $C_{6} H_{5} {NH}_{2}$

Correct Option is (D)

In general, arylamines are weaker bases than aliphatic amines.

Hence, aniline is the weakest base and its ${pK}_{b}$ value is the highest among the given amines.

3. ⇒ (MHT CET 2021 21th September Evening Shift )

Which among following amines has lowest ${pK}_{b}$ values?

A. ${CH}_{3} {CH}_{2} {NH}_{2}$

B. ${({CH}_{3} {CH}_{2})}_{2} NH$

C. ${({CH}_{3} {CH}_{2})}_{3} N$

D. $C_{6} H_{5} {NH}_{2}$

Correct Option is (B)

(CH $_{3}$ CH $_{2}$ ) $_{2}$ NH is secondary amine which is strong base and has lowest pK $_{b}$ value.

4. ⇒ (MHT CET 2021 21th September Morning Shift )

Which of the following conjugate bases is stabilized to greater extent due to solvation of ammonia and amines?

A. $R_{3} {NH}^{+}$

B. ${RNH}_{3}^{+}$

C. ${NH}_{4}^{+}$

D. $R_{2} {NH}_{2}^{+}$

Correct Option is (C)

${NH}_{4}^{\oplus}$ is best stabilized by solution while the stabilization by solvation is very poor in $R_{3} {NH}^{\oplus}$ . Order of stabilization: ${NH}_{4}^{\oplus} > R - {NH}_{3}^{\oplus} > R_{2} {NH}^{\oplus} > R_{3} {NH}^{\oplus}$

5. ⇒ (MHT CET 2021 21th September Morning Shift )

Which of the following amines acts as strongest base?

A. ${CH}_{3} {NH}_{2}$

B. $(C_{2} H_{5}) N {({CH}_{3})}_{2}$

C. ${({CH}_{3})}_{2} NH$

D. ${({CH}_{3})}_{3} N$

Correct Option is (C)

Secondary amines are the strongest bases.

$∴ ({CH}_{3})_{2} NH$ acts as strong base.

⇒Amines