Chemical and Ionic Equilibrium 1 Question 30

31. The equilibrium $2 \mathrm{Cu}^{\mathrm{I}} \rightleftharpoons \mathrm{Cu}^{0}+\mathrm{Cu}^{\mathrm{II}}$ in aqueous medium at $25^{\circ} \mathrm{C}$ shifts towards the left in the presence of

(2011)

(a) $\mathrm{NO}_{3}^{-}$

(b) $\mathrm{Cl}^{-}$

(c) $\mathrm{SCN}^{-}$

(d) $\mathrm{CN}^{-}$

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Solution:

  1. $\mathrm{Cl}^{-}, \mathrm{CN}^{-}$and $\mathrm{SCN}^{-}$forms precipitate with $\mathrm{Cu}(\mathrm{I})$, remove $\mathrm{Cu}$ (I) ion from equilibrium and reaction shifts in backward direction according to Le-Chatelier’s principle.