Redox Reactions And Electrochemistry Ques 617
Question: In the silver plating of copper, $ K[Ag{{(CN)}_2}] $ is used instead of $ AgNO_3 $ . The reason is
Options:
A) a thin layer of Ag is formed on Cu
B) more voltage is required
C) $ A{g^{+}} $ ions are completely removed from solution
D) less availability of $ A{g^{+}} $ ions, as Cu cannot displace Ag from $ {{[Ag{{( CN )}_2}]}^{-}} $ ion
Show Answer
Answer:
Correct Answer: D
Solution:
[d] In the silver plating of copper, $ K[Ag{{( CN )}_2}] $ is used instead of $ AgNO_3 $ .
Copper being more electropositive readily precipitate silver from their salt solution $ Cu+2AgNO_3\xrightarrow{{}}Cu{{( NO_3 )}_2}+Ag $ whereas in $ K[Ag{{(CN)}_2}] $ solution a complex anion $ {{[Ag{{(CN)}_2}]}^{-}} $ is formed and hence $ A{g^{+}} $ are less available in the solution and therefore copper cannot displace Ag from its complex ion.
