Question

$AgCl$ is colourless whereas $AgI$ is yellow, because of

• A. $A{g}^{+}$ have $18$ electron shell to screen the nuclear charge
• B. $A{g}^{+}$ shows pseudo inert gas configuration
• C. Distortion of $I^{-}$ is more pronounced than $C{l}^{-}$ ion
• D. Existence of $d-d$ transition

Answer 1

The correct option is C Distortion of $I^{-}$ is more pronounced than $C{l}^{-}$ ion

The colour of $AgI$ can be explained on the basis of the polarisation of the bigger negative ion. The anion $I^{-}$ is more polarised. Hence the electrons get excited by partial absortion of visible light and shows yellow colour.