n-factor of k2cr2o7 in acidic med?
n-factor can be simply defined as the change in the oxidation state of a particular ion. This will be equal to the number of electrons gained or lost by that species during the reaction. Another important point to note is that the term n-factor is used with reference to a single species and not the overall equation involving both the ions. That is, it is calculated with respect to a particular ion, or a half reaction involving only that particular ion.
Potassium dichromate in acidic medium, acts as oxidizing agent and its oxidising action can be represented as follows:
Cr2O72− + 14H+ + 6e− → 2Cr3+ + 7H2O (Eθ = 1.33V)
Cromate ion is changing from +6 oxidation state to +3 oxidation state. In other words, this reaction involves the exchange of 6 electrons, hence the n factor is 6.