GATE 2023 Civil Engineering PYQ

Question

The theoretical aerobic oxidation of biomass (C₅H₇O₂N) is given below:

C₅H₇O₂N + 5O₂ → 5CO₂ + NH₃ + 2H₂O

The biochemical oxidation of biomass is assumed as a first-order reaction with a rate constant of 0.23/d at 20ºC (logarithm to base e). Neglecting the second-stage oxygen demand from its biochemical oxidation, the ratio of BOD₅ at 20ºC to total organic carbon (TOC) of biomass is _______ (round off to two decimal places).

[Consider the atomic weights of C, H, O and N as 12 g/mol, 1 g/mol, 16 g/mol and 14 g/mol, respectively