Q59 / 180 · KCET 2020 · Chemistry
A sol of $\mathrm{AgI}$ is prepared by mixing equal volumes of $0.1 \mathrm{M} \mathrm{AgNO}_{3}$ and $0.2 \mathrm{M} \mathrm{KI}$, which of the following statement is correct?
- ASol obtained is a negative sol with $\mathrm{NO}_{3}^{-}$ adsorbed on AgI.
- BSol obtained is a positive sol with $\mathrm{Ag}^{+}$ adsorbed on AgI.
- CSol obtained is a positive sol with $\mathrm{K}^{+}$adsorbed on AgI.
- Correct answerDSol obtained is a negative sol with $\mathrm{I}^{-}{ }^{-}$adsorbed on AgI.
Solution
Whenever a sol of silver iodide is prepared by mixing equal volumes of $0.1 \mathrm{M} \mathrm{AgNO}_{3}$ and $0.2$ $\mathrm{M} \mathrm{KI}$, the sol will be a negative sol with $\mathrm{I}^{-}$ adsorbed on AgI. The reaction will be.
$\mathrm{AgNO}_{3}+\mathrm{KI} \longrightarrow \mathrm{AgI}+\mathrm{KNO}_{3}$
Here, molarity of $\mathrm{KI}$ is more than that of $\mathrm{AgNO}_{3}$ and hence, $\mathrm{I}^{-}$will be adsorbed on AgI to produce a negative sol.
Hence, the correct answer is option: 'D'.