Question

The silver salts like $\mathrm{AgBr}$ and $\mathrm{AgI}$ are colored because of

• A. d-d transition of electrons
• B. charge transfer
• C. both A and B
• D. Polarisation of halid ${\mathrm{Ag}}^{+}$

Answer 1

The correct option is D

Polarisation of halid ${\mathrm{Ag}}^{+}$

Explanation:

Silver:

• Silver$\left(\mathrm{Ag}\right)$ is a transition metal with an atomic number $47$.
• The electronic configuration of silver is $[Kr]4d^{10}5s^1$.
• In silver ion$\left({\mathrm{Ag}}^{+}\right)$, one electron is removed from the outermost s-orbital. So the electronic configuration of $A{g}^{+}$is $[Kr]4d^{10}$.
• In the $\mathrm{d}-$orbital of $A{g}^{+}$, all the electrons are paired.
• As no unpaired electrons are present $\mathrm{d}-\mathrm{d}$ transition cannot take place. The color of the compound $\mathrm{AgCl}$ is white but the silver salt of $\mathrm{AgBr}$ and $\mathrm{AgI}$ are colored.
• The property of an anion to get polarized by the deformation of the electron cloud formed by the cation is known as polarization. As the polarization increases, the intensity of compound color increases.
• The silver salts like Silver Bromide $\mathrm{AgBr}$ and Silver iodide $\mathrm{AgI}$ are colored because of the polarization of halogen anion by the silver cation as the intensity of the compound's color increases with an increase in polarization.

Hence, the correct option is D. The silver salts like $\mathrm{AgBr}$ and $\mathrm{AgI}$ are colored because of polarisation of ${\mathrm{Ag}}^{+}$.