The Lewis acid character of boron tri halides follows the order :
The Lewis acid character of boron tri halides follows the order :
Show Hint
- $BCl _3> BF _3> BBr _3> BI _3$
- $BI _3> BBr _3> BCl _3> BF _3$
- $BBr _3> BI _3> BCl _3> BF _3$
- $BF _3> BCl _3> BBr _3> BI _3$
The Correct Option is B
Approach Solution - 1
So, the correct option is (B).
Approach Solution -2
Extent of back bonding reduces down the group leading to more Lewis acidic strength.
For example, \( \text{BF}_3 \) has the most extent of back bonding due to the \( 2p - 2p \) interaction, whereas \( \text{BCl}_3 \) and \( \text{BBr}_3 \) show less back bonding.
Therefore, the Lewis acid strength increases from \( \text{BF}_3 \) to \( \text{BCl}_3 \), \( \text{BBr}_3 \), and finally \( \text{B}_1 \).
Thus, the correct order is \( \text{B}_1 > \text{BBr}_3 > \text{BCl}_3 > \text{BF}_3 \).
Top Questions on p -Block Elements
Method used for separation of mixture of products (B and C) obtained in the following reaction is:
- JEE Main - 2026
- Chemistry
- p -Block Elements
- Given below are two statements:
Statement I: [CoBr₄]²⁻ ion will absorb light of lower energy than [CoCl₄]²⁻ ion.
Statement II: In [CoBr₄]²⁻ ion, the energy separation between the two set of d-orbitals is more than [CoCl₄]²⁻ ion.
In the light of the above statements, choose the correct answer from the options given below :- JEE Main - 2026
- Chemistry
- p -Block Elements
- Given below are two statements: Statement I: Elements \(X\) and \(Y\) are the most and least electronegative elements, respectively, among \(N\), \(As\), \(Sb\) and \(P\). The nature of the oxides \(X_2O_3\) and \(Y_2O_3\) is acidic and amphoteric, respectively. Statement II: \(BCl_3\) is covalent in nature and gets hydrolysed in water. It produces \([B(OH)_4]^-\) and \([B(H_2O)_6]^{3+}\) in aqueous medium. In the light of the above statements, choose the correct answer from the options given below:
- JEE Main - 2026
- Chemistry
- p -Block Elements
- Write chemical formula of epsom salt. Give two uses of \( H_2SO_4 \).
- Maharashtra Class XII - 2026
- Chemistry
- p -Block Elements
- Write general characteristics of interhalogen compounds.
- Maharashtra Class XII - 2026
- Chemistry
- p -Block Elements
Questions Asked in JEE Main exam
MX is a sparingly soluble salt that follows the given solubility equilibrium at 298 K.
MX(s) $\rightleftharpoons M^{+(aq) }+ X^{-}(aq)$; $K_{sp} = 10^{-10}$
If the standard reduction potential for $M^{+}(aq) + e^{-} \rightarrow M(s)$ is $(E^{\circ}_{M^{+}/M}) = 0.79$ V, then the value of the standard reduction potential for the metal/metal insoluble salt electrode $E^{\circ}_{X^{-}/MX(s)/M}$ is ____________ mV. (nearest integer)
[Given : $\frac{2.303 RT}{F} = 0.059$ V]- JEE Main - 2026
- Electrochemistry
An infinitely long straight wire carrying current $I$ is bent in a planar shape as shown in the diagram. The radius of the circular part is $r$. The magnetic field at the centre $O$ of the circular loop is :
- JEE Main - 2026
- Current electricity
- For two identical cells each having emf \(E\) and internal resistance \(r\), the current through an external resistor of \(6\,\Omega\) is the same when the cells are connected in series as well as in parallel. The value of the internal resistance \(r\) is ________ \(\Omega\).
- JEE Main - 2026
- Current electricity
- The half-life of $^{65}$Zn is 245 days. After $x$ days, 75% of the original activity remained. The value of $x$ in days is __________ (Nearest integer).}
(Given: $\log 3 = 0.4771$ and $\log 2 = 0.3010$)- JEE Main - 2026
- Surface Chemistry
- The hydrogen spectrum consists of several spectral lines in Lyman series (L$_1$, L$_2$, L$_3$ ...; L$_1$ has lowest energy among Lyman series). Similarly, it consists of several spectral lines in Balmer series (B$_1$, B$_2$, B$_3$ ...; B$_1$ has lowest energy among Balmer lines). The energy of L$_1$ is $x$ times the energy of B$_1$. The value of $x$ is ___ $\times 10^{-1}$. (Nearest integer)
- JEE Main - 2026
- Atomic Structure
Concepts Used:
P-Block Elements
- P block elements are those in which the last electron enters any of the three p-orbitals of their respective shells. Since a p-subshell has three degenerate p-orbitals each of which can accommodate two electrons, therefore in all there are six groups of p-block elements.
- P block elements are shiny and usually a good conductor of electricity and heat as they have a tendency to lose an electron. You will find some amazing properties of elements in a P-block element like gallium. It’s a metal that can melt in the palm of your hand. Silicon is also one of the most important metalloids of the p-block group as it is an important component of glass.
P block elements consist of:
- Group 13 Elements: Boron family
- Group 14 Elements: Carbon family
- Group 15 Elements: Nitrogen family
- Group 16 Elements: Oxygen family
- Group 17 Elements: Fluorine family
- Group 18 Elements: Neon family