Tag: classical idea of redox reactions

Questions Related to classical idea of redox reactions

Which of the following is a non - redox process ?

bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

  1. $ SO _{4}^{2-}\rightarrow SO _{3} $

  2. $ Cr _{2}O _{7}^{2-}\rightarrow CrO _{4}^{2-} $

  3. $ PO _{4}^{3-}\rightarrow P _{2}O _{7}^{4-} $

  4. $ C _{2}O _{4}^{-2}\rightarrow CO _{2} $

Show answer
Correct Option: A,B,C
Explanation:

In Redox reaction oxidation state changes  


(a) In $ SO _{4}^{-2}, $ Its $ S^{+6} $
In $ SO _{3}, $ Its $ S^{+6}$
$ \therefore$ In $SO _{4}^{-2}\rightarrow SO _{3},$ there is no change 
in oxidation state of $ O^{+5}$
$ \therefore $ Non- redox reaction 

(b) In $ Cr _{2}O _{7}^{-2} $
Lets oxidation state of Cr be x 
$ \therefore 2(x)+7(-2) = -2 $
$ \therefore 2x+(-14) = -2 $
$ \therefore 2x = 12 $
$ \therefore x = 16 $

In $ CrO _{4}^{-2} $ 

Let oxidation Sate of Cr be y
$ y+4(-2) = -2 $
$ y-8 = -2 $
$ y = +6 $
$ \therefore $ oxidation of Cr remain same 
$ \therefore $ Non- redox Readtion

(C) In $ PO _{4}^{-3}, $ Its $ P^{+} $
and In $ P _{2}O _{7}^{-4} $
Let oxidation sate of P be x 
$ 2x+7(-2) = -4 $
$ 2x-14 = -4 $
$ \therefore 2x = 10 $  $ \therefore $ Non - redox Reaction 
$ \therefore x = 5 $

(d) In $ C _{2}O _{4}^{-2},$ Its $ C^{+3}$
In $ Co _{2},$ Its $ C^{+4} $  $ \therefore $ Redox reaction 

Hence, the correct options are $\text{A}$, $\text{B}$ and $\text {C}$