(i) Explain why AgCl is white in colour whereas AgI is yellow. (ii) if the degree of polarisation of the anion is (e.g. PbI_(2) is yellow) but if it is lower, then the compound is either white or colourless (e.g., PbCl_(2) is white)- why?

(i) Explain why AgCl is white in colour whereas AgI is yellow. (ii) if

1.	(i) Explain why AgCl is white in colour whereas AgI is yellow. (ii) if the degree of polarisation of the anion is (e.g. PbI_(2) is yellow) but if it is lower, then the compound is either white or colourless (e.g., PbCl_(2) is white)- why?
Answer» Solution :(i) LARGER the ANIONIC radius, greater is its tendency to get polarised. The higher polarisability of `I^(-)` ion, owing to its larger radius, facilitates the transition of electron (from anion to metal ion) in the visible range, imparting yellow colour to AgI. on the other hand, lower polarisability of `Cl^(-)` ion, facilitates the transition of electron in the UV range. HENCE, AgCl appears white. (II) N/A