Question

Write redox reactions for the following:

1) C₆H₁₂O₆, if partially oxidized to C₆H₁₀O₇

2) C₅H₇O₂N if oxidized to CO₂ and NH₃

Answer 1

1) C6H12O6, if partially oxidized to C6H10O7

We begin to balance of our equations in the same was as before by balancing the major atoms first. Let us consider Glucose as a substrate

C6H12O6 --------> C6H10O7

Balance the major atoms, such as C and/or N.

C6H12O6 --------> C6H10O7   already balanced

Balance the oxygen with water. (as it is oxidation)

C6H12O6 + O2 --------> C6H10O7 + H2O

No need to balance Hydrogen with H+.

Note that there are no electrons needed to balance the equation. This results because there is no net oxidation or reduction.

2) C5H7O2N if oxidized to CO2 and NH3

C5H7O2N + 5 O2 --------> 5 CO2 + NH3 + 2 H2O

The above equation is written with two half reactions as before, balanced and assuming the end product for nitrogen is ammonia. This assumes that there is no nitrification.

If end product was NH4+, then we needed to add extra H+, as given below.

C5H7O2N + 5 O2 + H+ --------> 5 CO2 + NH4+ + 2 H2O