Arrange the following in increasing order of their pK\(_b\) values.
Arrange the following in increasing order of their pK\(_b\) values.
Show Hint
A < B < C
C < B < A
B < C < A
A < C < B
The Correct Option is B
Solution and Explanation
The pKb value of an amine is inversely related to its basic strength - lower pKb means stronger base.
1. Ethylamine (C):
- Strongest base because the ethyl (-C2H5) group donates electrons, increasing the availability of the lone pair on nitrogen.
- Lowest pKb value.
2. Benzylamine (B):
- Less basic than ethylamine because the benzyl (-CH2C6H5) group has a weak +I effect but does not strongly delocalize electrons.
3. Aniline (A):
- Weakest base because the nitrogen lone pair is delocalized over the benzene ring, reducing its availability for protonation.
- Highest pKb value.
Thus, the increasing order of pKb values is:
C (Ethylamine) < B (Benzylamine) < A (Aniline)
So, the correct answer is (B): C < B < A
Top AP EAMCET Chemistry Questions
- If the $pK_a$ of acetic acid and $pK_b$ of dimethylamine are $4.76$ and $3.26$ respectively, the pH of dimethyl ammonium acetate solution is
- In the first order thermal decomposition of $C _{2} H _{5} I (g) \longrightarrow C _{2} H _{4}(g)+ HI (g)$, the reactant in the beginning exerts a pressure of $2$ bar in a closed vessel at $600 \,K$. If the partial pressure of the reactant is $0.1$ bar after $1000$ minutes at the same temperature the rate constant in $\min ^{-1}$ is $(\log 2=0.3010)$
- Isopropyl benzene on aerial oxidation followed by acid hydrolysis of the resulting compound yields
- Sodium nitrite is reacted with $H_2SO_4$ to form $NaHSO_4, HNO_3$, water and $X$. Gold is dissolved in aqua-regia to form water, $AuCl^{-}_4$ and $Y. X$ and $Y$ are respectively
- The average translational kinetic energy of a molecule in a gas becomes equal to $0.69\, eV$ at a temperature about [Boltzmann constant = $1.38 \times 10^{-23} \; J \; K^{-1}$]
Top AP EAMCET Molecular Polarity Questions
The mass of particle X is four times the mass of particle Y. The velocity of particle Y is four times the velocity of X. The ratio of de Broglie wavelengths of X and Y is:
The correct set of four quantum numbers for an electron in a 4d subshell is:
Electronic configurations of four elements A, B, C, and D are given below: \[ {A: } 1s^2 2s^2 2p^4, \quad {B: } 1s^2 2s^2 2p^6 3s^1, \quad {C: } 1s^2 2s^2 2p^6, \quad {D: } 1s^2 2s^2 2p^5 \] The correct order of increasing tendency to gain electrons is:
Which of the following sets are not correctly matched?
i. XeF₄ - sp³
ii. SF₄ - sp³d
iii. SO₃ - sp²
iv. SnCl₂ - spThe number of molecules having one lone pair of electrons on the central atom is from the following list: SnCl$_2$, XeF$_6$, SO$_3$, ClF$_3$, BrF$_5$, H$_2$O, XeO$_3$.
Top AP EAMCET Questions
- If $\int \cos x . \cos 2x . \cos 5x dx = A \; \sin 2x + B \sin 4x + C \sin 6x + D \sin 8x + k $ (where $k$ is the arbitrary constant of integration), then $\frac{1}{B} + \frac{1}{C} = $
- If $k$ is one of the roots of the equation $x^2 - 25x + 24 = 0 $ such that $A = \begin{bmatrix}1&2&1\\ 3&2&3\\ 1&1&k\end{bmatrix} $ is a non-singular matrix, then $A^{-1}$ =
- If only $\frac{1}{51}^{th}$ ot the main current is to be passed through a galvanometer then the shunt required is $R_1$ and if only $\frac{1}{11}^{th}$ of the main voltage is to be developed across the galvanometer, then the resistance required is $R_2$. Then $\frac{R_2}{R_1} =$
- If $p$ and $q$ are respectively the global maximum and global minimum of the function $f(x) = x^2 e^{2x}$ on the interval $[-2, 2]$ , then $pe^{-4} + qe^4 = $
- If $\displaystyle\sum^n_{k - 1} \tan^{-1} \left( \frac{1}{k^2 + k + 1} \right) = \tan^{-1} (\theta) $ , then $\theta$ =