`PbO_2` is stronger oxidizing agent than` SnO_2`, why ?

Explain the following observations : Despite lower value of its electron gain enthalpy with negative sign, fluorine (F_2) is a stronger oxidising agent than Cl_2 .

Although electron gain enthalpy of fluorine is less negative as compared to chlorine, fluorine is stronger oxidizing agent than chlorine. Why?

Bi (V) is a stronger oxidising agent than Sb (V). Why ?

Although electron gain enthalpy of fluorine is less negative as compared to chlorine, fluorine is a stronger oxidising agent than chlorine. Why ?

BrO_4^- is stronger /weaker oxidiaing agent than CIO_4^- .

H_3PO_2 is a stronger reducing agent than H_3PO_3 . Give reasons..

In aqueous solution, Cr^(2+) is stronger reducing agent than Fe^(2+) . This is because

How would you account for the following ? Cr^(2+) is stronger reducing agent than Fe^(2+) .

How would you account for the following : The electron gain enthalpy with negative sign for fluorine is less than that for chlorine, still fluorine is a stronger oxidising agent than chlorine.