Question

A 25 ml of sewage water sample was refluxed with 10 ml 0f 0.25 N K2Cr2 O7 solution. The untreated potassium dichromate requires 6.5 ml of 0.1 N FAS. 10 ml of potassium dichromate solution and 25 ml distilled water , under the same condition as sample required 27 ml of 0.1 n FAS. Calculate the COD of sewage.



1 . 650 mg/liter

2 . 656 mg/liter

3 . 550 mg/liter

4 . 100 mg/liter

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Answer 1

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Methane is a chemical compound with the chemical formula CH₄. It is a group-14 hydride and the simplest alkane, and is the main constituent of natural gas.