Redox Reactions And Electrochemistry Ques 127
Question: The standard oxidation potential of zinc and silver in water at $ 298K $ are $ Zn(s)\to Z{n^{2+}}+2{e^{-}},;,E=0.76,V $ $ Ag(s)\to ,A{g^{2+}}+2{e^{-}},;,E=-0.80,V $ Which of the following reactions actually take place [NCERT 1983, 84; KCET 2003]
Options:
A) $ Zn(s)+2A{g^{+}}(aq),\to ,Z{n^{++}}(aq)+2Ag(s) $
B) $ Z{n^{++}}(aq)+2Ag(s),\to ,2A{g^{+}}(aq)+Zn(s) $
C) $ Zn(s)+Ag(s),\to ,Z{n^{++}}(aq)+A{g^{+}}(aq) $
D) $ Z{n^{++}}(aq)+A{g^{+}}(aq),\to ,Zn(s)+Ag(s) $
Show Answer
Answer:
Correct Answer: A
Solution:
$ \overset{o}{\mathop{Z{n_{(s)}}}},+2Ag_{(aq)}^{+}\to Zn_{(aq)}^{2+}+\overset{o}{\mathop{2A{g_{(s)}}}}, $ In this reaction zinc act as a anode and $ Ag $ act as a cathode.
