Question

Determine if the following chemical reactions are oxidation-reduction reactions or not. If the chemical reaction is NOT a redox reaction, write NONREDOX; otherwise, balance it by oxidation number method and determine the oxidizing and reducing agents. Show your solution following the step-by-step process of the said method

K₂​Cr₂​O₄ + H₂O₂ ​+ HCl → KCl + CrCl3₃ + O₂ + H2​O

Answer 1

here,

This is an oxidation-reduction  (redox) reaction ;

$6 O^{-{I}} - 6 e^- → 6 O^{0}$  (oxidation)

$2 Cr^{VI }+ 6 e- → 2 Cr^{III}$  (reduction)

H₂O₂ is a reducing agent; 

K₂Cr₂O₇ is an oxidizing agent.

balanced equation:

3 H₂O₂^(-I) + K₂Cr₂O₇^(VI)+ 8 HCl → 

2 CrCl₃^(III) +  KCl + 3 O₂⁽⁰⁾ + 7 H₂O

steps:

unbalanced equation

K₂​Cr₂​O₄ + H₂O₂ ​+ HCl → KCl + CrCl3₃ + O₂ + H2​O

Assign oxidation number

Identify and write all redox couples in reaction:

Balance the atoms in each half reaction

and also charge,

then combine reactions to get our final reaction:

:3 H₂O₂^(-I) + K₂Cr₂O₇^(VI)+ 8 HCl → 

2 CrCl₃^(III) +  KCl + 3 O₂⁽⁰⁾ + 7 H₂O