Question

Assuming standard conditions, arrange the following in order of decreasing strength as oxidizing agents in acidic solution: Cr2O2−7,H2O2,Cu2+,Cl2,O2.

I understand that stronger oxidizing agents have more positive cell potentials but how would I figure this out if I weren't given the cell potentials?

Answer 1

Answer – We are given compounds and need to order of decreasing strength as oxidizing agents in acidic solution.

W know higher cell potential is the stronger oxidizing agent. We need to look for the cell potential for each element form the given compounds.

From the standard reduction potential table for Cr²⁺ it is 1.33 V

H₂O₂ is 1.77 V , Cu²⁺ is 0.34 V , Cl₂ is 1.36 V and for O₂ it is 1.23 V

We know Cr oxidation state in Cr₂O₇^2- is 6+.

From the above value of cell potential order of decreasing the strength as oxidizing agents in acidic solution as follow –

H₂O₂ > Cl₂ > Cr₂O₇^2- > O₂ > Cu²⁺