wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

In the following reaction :

H2O2(aq)+Cl2O7(aq)ClO2(aq)+O2(g)

calculate the moles of OH and H2O respectively present in a balanced equation in a basic medium :

A
3,6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
4,6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2,5
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
4,4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 2,5
H2O2(aq)+Cl2O7(aq)ClO2(aq)+O2(g)

Oxidation state of O in H2O2=1
Oxidation state of O in O2=0
Oxidation state of Cl in Cl2O7=+7
Oxidation state of Cl in ClO2=+3

Clearly, H2O2 is undergoing oxidation and Cl2O7 is undergoing reduction.
using the formula of n-factor given above,
nf of H2O2=2
nf of Cl2O7=8
simplest ratio of nf of H2O2:Cl2O7 is 1:4

Cross multiplying these with nf of each other.
we get,
4H2O2(aq)+Cl2O7(aq)ClO2(aq)+O2(g)

Balancing the main elements on both sides, generally oxygen is not balanced in this step but we will balance as it is undergoing oxidation in this reaction.

4H2O2(aq)+Cl2O7(aq)2ClO2(aq)+4O2(g)

Adding the H2O to balance the oxygen,


4H2O2(aq)+Cl2O7(aq)2ClO2(aq)+4O2(g)+3H2O

Adding H+ to balance hydrogen,

4H2O2(aq)+Cl2O7(aq)2ClO2(aq)+4O2(g)+3H2O+2H+

Now adding OH to both sides to combine with H+ and make it H2O,
4H2O2(aq)+Cl2O7(aq)+2OH2ClO2(aq)+4O2(g)+3H2O+2H++2OH

4H2O2(aq)+Cl2O7(aq)+2OH2ClO2(aq)+4O2(g)+5H2O

This is the final balanced equation.

We can also see that charge on both sides is -2. which also indicates that the equation is balanced now.

4H2O2(aq)+Cl2O7(aq)+2OH2ClO2(aq)+4O2(g)+5H2O

So, 2, 5 moles of OH and H2O respectively are present in balanced equation.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon