Question:
Identify the amine having highest $\text{p}\text{K}_{\text{b}}$ value.
Identify the amine having highest $\text{p}\text{K}_{\text{b}}$ value.
Show Hint
Basicity $\propto \frac{1}{pK_b}$. Aromatic amines (lone pair in resonance) are always weaker than aliphatic amines.
Updated On: Apr 26, 2026
- $(\text{CH}_3)_3\text{N}$
- $\text{C}_6\text{H}_5\text{CH}_2\text{NH}_2$
- $\text{C}_6\text{H}_5\text{NH}_2$
- $(\text{CH}_3)_2\text{NH}$
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Concept
Highest $pK_b$ value = Weakest base.
Step 2: Basicity Trend
- Aliphatic amines are more basic than ammonia. - Aromatic amines (like Aniline, $C_6H_5NH_2$) are significantly weaker bases because the lone pair on Nitrogen is delocalized into the benzene ring. - (B) is Benzylamine, where the $-NH_2$ is not directly on the ring, so it is more basic than aniline.
Step 3: Conclusion
Aniline is the weakest base among the options, thus having the highest $pK_b$.
Final Answer: (C)
Highest $pK_b$ value = Weakest base.
Step 2: Basicity Trend
- Aliphatic amines are more basic than ammonia. - Aromatic amines (like Aniline, $C_6H_5NH_2$) are significantly weaker bases because the lone pair on Nitrogen is delocalized into the benzene ring. - (B) is Benzylamine, where the $-NH_2$ is not directly on the ring, so it is more basic than aniline.
Step 3: Conclusion
Aniline is the weakest base among the options, thus having the highest $pK_b$.
Final Answer: (C)
Was this answer helpful?
0
0
Top MHT CET Chemistry Questions
- The temperature of $32^{\circ}C$ is equivalent to
- The heat of formation of water is $ 260\, kJ $ . How much $ H_2O $ is decomposed by $ 130\, kJ $ of heat ?
- If a metal crystallises in bcc structure with edge length of unit cell $4.29 \times 10^{-8}\, cm$ the radius of metal atom is
- Which of the following oxides can act both as an oxidising agent as well as reducing agent ?
- "The mass and energy both are conserved in an isolated system", is the statement of
View More Questions
Top MHT CET Gas laws Questions
- The relationship between solubility of a gas in a liquid at constant temperature and external pressure is:
- What is the rate law if the rate is directly proportional to \([B]^2\) and independent of \([A]\)?
- A gas occupies a volume of 5.0 L at 300 K and 1.0 atm pressure. What will be the volume of the gas if the pressure is increased to 2.0 atm while the temperature is kept constant?
- Which of the following is the correct value of the molar volume of an ideal gas at standard temperature and pressure (STP)?
- A sample of an ideal gas occupies 10 liters at a pressure of 2 atm and a temperature of 300 K. What is the volume of the gas at 1 atm pressure and 300 K temperature?
View More Questions
Top MHT CET Questions
- During r- DNA technology, which one of the following enzymes is used for cleaving DNA molecule ?
- In non uniform circular motion, the ratio of tangential to radial acceleration is (r = radius of circle, $v =$ speed of the particle, $\alpha =$ angular acceleration)
- The temperature of $32^{\circ}C$ is equivalent to
- The line $5x + y - 1 = 0$ coincides with one of the lines given by $5x^2 + xy - kx - 2y + 2 = 0 $ then the value of k is
- The heat of formation of water is $ 260\, kJ $ . How much $ H_2O $ is decomposed by $ 130\, kJ $ of heat ?
View More Questions