question_answer

The \[{{K}_{sp}}\] of \[A{{g}_{2}}Cr{{O}_{4}},\,AgCl,\,AgBr\] and \[AgI\] are respectively, \[1.1\times {{10}^{-12}},\,\,1.8\times {{10}^{-10}}\]\[5.0\times {{10}^{-13}},\]\[8.3\times {{10}^{-17}}\]. Which one of the following salts will precipitate last if \[AgN{{O}_{3}}\] solution is added to the solution containing equal moles of \[NaCl,NaBr,NaI\] and\[N{{a}_{2}}CrC{{O}_{4}}\].                                                                                              [NEET 2015 ]

A)  \[Agl\]             

B)                   \[AgCl\]

C)  \[AgBr\]       

D)  \[A{{g}_{2}}Cr{{O}_{4}}\]

Correct Answer: D

Solution :

Solubility product

Solubility of  is highest.

So, it will precipitate last.