Let the solubilities of AgCl in `H_(2)O`, and in 0.01 M `CaCl_(2)` 0.01 M NaCl, and 0.05 M `AgNO_(3)` be `S_(1), S_(2), S_(3), S_(4)`, respectively. What is the correct relationship between these quantities.  

Options

A. `S_(1) gt S_(2) gt S_(3) gt S_(4)`
B. `S_(1) gt S_(2) = S_(3) gt S_(4)`
C. `S_(1) gt S_(3) gt S_(2) gt S_(4)`
D. `S_(4) gt S_(2) gt S_(3) gt S_(1)`

Answer

C

Explanation

(i) `AgCl + H_(2)O rarr Ag^(o+)(aq) + Cl^(ɵ)(aq) ……S_(1)`
(ii) AgCl in 0.01 M `CaCl_(2), " " ……. S_(2)`
Concentration of `Cl^(ɵ)= 2 xx 0.01 = 0.02 M`
(iii) AgCl in 0.01 M NaCl, `" "S_(3)`
Concentration of `Cl^(ɵ) = 0.01 M`
(iv) AgCl is 0.05 M. `AgNO_(3), " " ........ S_(4)`
Concentration of `Ag^(o+) = 0.05`
Since both `Cl^(ɵ)` ions and `Ag^(o+)` ions acts as common ion. So larger the concentration of `Ag^(o+)` or `Cl^(ɵ)` ions, more is the suppression of ionisation of AgCl and hence less will be solubility of AgCl.
`therefore` Solubliity order
`S_(1) gt S_(3) gt S_(2) gt S_(4)`