NEET2015ChemistryEnvironmental ChemistryActual
500 mL of a sample of water required 19.6 mg of K ₂ Cr ₂ O ₇ for the oxidation of dissolved organic matter in it in the presence of H ₂ SO ₄ . The COD of water sample is
Options
- A3.2 ppm
- B7.2 ppm
- C6.4 ppm
- D4.6 ppm
Correct answer
C. 6.4 ppm
Step-by-step solution
aligned & 500 ~mL H H ₂ O 19.6 10⁻³ ~g ~K ₂ Cr ₂ O ₇ & 106 ~mL H ₂ O 39.2 ~g ~K ₂ Cr ₂ O ₇ & 49 ~g of K ₂ Cr ₂ O ₇ 8 ~g of O ₂ & 39.2 ~g of K ₂ C ₂ O ₇ 6.4 ~g of O ₂ & COD =6.4 ppm & aligned