100 ml of a sample of water requires 1.96 mg of potassium dichromate in the presence of 50% H_2SO_4 for the oxidation of dissolved organic matter in it. Calculate the chemical oxygen demand.

100 ml of a sample of water requires 1.96 mg of potassium dichromate i

1.	100 ml of a sample of water requires 1.96 mg of potassium dichromate in the presence of 50% H_2SO_4 for the oxidation of dissolved organic matter in it. Calculate the chemical oxygen demand.
Answer» <html><body><p></p>Solution :One gram equivalent of any <a href="https://interviewquestions.tuteehub.com/tag/oxidant-1144439" style="font-weight:bold;" target="_blank" title="Click to know more about OXIDANT">OXIDANT</a> can give, one equivalent weight of <a href="https://interviewquestions.tuteehub.com/tag/oxygen-1144542" style="font-weight:bold;" target="_blank" title="Click to know more about OXYGEN">OXYGEN</a> (8 <a href="https://interviewquestions.tuteehub.com/tag/g-1003017" style="font-weight:bold;" target="_blank" title="Click to know more about G">G</a>) <br/> `49 g K_2Cr_2O_7 to 8g " Oxygen"` <br/> ` 1.96 xx 10^(-3) g K_2Cr_2O_7 to (8 xx 1.96 xx 10^(-3))/(49)=0.32 mg ` <br/> Chemical oxygen demand of the given <a href="https://interviewquestions.tuteehub.com/tag/100-263808" style="font-weight:bold;" target="_blank" title="Click to know more about 100">100</a> ml <a href="https://interviewquestions.tuteehub.com/tag/sample-1194587" style="font-weight:bold;" target="_blank" title="Click to know more about SAMPLE">SAMPLE</a> of water `=(0.32)/(0.1) = 3.2 ppm`</body></html>