By how much is the oxidizing power of `Cr_2O_7^(2-)"|"Cr^(3+)` couple decreased if the `H^+` concentration is decreased from 1M to `10^(-30`M at `25^(@)` C?

By how much is the oxidizing power of Cr_2O_7^(2-)"|"Cr^(3+) couple decreased if the H^+ concentration is decreased from 1M to 10^(-3 M at 25^(@) C?

By how much is the oxidizing power of Cr_2O_7^(2-)"|"Cr^(3+) couple decreased if the H^+ concentration is decreased from 1M to 10^(-3 M at 25^(@) C?

How much is the oxidising power of the MnO_4^(-) (1M)|Mn^(2+) (1M) couple decreased if the H^+ concentration is decreased from 1M to 10^-4 M at 25^@C

By how much is the oxidizing power of the MnO_4//Mn^(+2) couple decreased if the H^+ concentration is decreased by 100 at 25^@C? Assume other species have no change in concentration.

What is the oxidation number of Cr in Cr_2O_7^(2-) ?

What is the oxidation number of Cr in Cr_(2)O_(7)^(2-) ?