Redox Reactions And Electrochemistry Ques 497
Question: Which one of the following reactions does not involve either oxidation or reduction [EAMCET 1982]
Options:
A) $ VO_2^{+},\to ,V_2O_3 $
B) $ Na,\to ,N{{a}^{+}} $
C) $ CrO_4^{2-},\to ,Cr_2O_7^{2-} $
D) $ Z{{n}^{2+}},\to ,Zn $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \overset{*}{\mathop{CrO_4^{2-}}}, $
$ \overset{*,}{\mathop{Cr_2O_7^{2-}}}, $ $ x+[(-2)\times 4]=-2 $
$ 2x+(-2)\times 7=-2 $ $ x=8-2=+6 $ $ 2x=14-2=12 $ ,
$ x=\frac{12}{2}=+6 $ In this reaction oxidation and reduction are not involved because there is no change in oxidation number.
