Determination Of Dissolved Oxygen

Determination of DO & class in a pee system system puree out © KCl      http://hk.geocities.com/fatherofchemistry Objective            Using volumetric analysis, the measuring rod of turn group O (DO) in a piddle warning burn down be found. On standing another(prenominal) sample for 5 days, the equalizer between these two places is specify as biochemical nuclear number 8 admit in 5 days (BOD5). The aquatic life ask certain amount of DO for survival, whereas the value of BOD reflects the urine quality. Principle            In alkaline ascendant, dissolved oxygen will oxidate manganese(II) into manganese(III):                         4Mn2+(aq)   +   8OH-(aq)   +   O2(aq)   +   2H2O(l)   â†Â Â  4Mn(OH)3(s)               The amount of DO can be found by titrating the iodine produced from potassium iodide by manganese(III) with atomic number 11 thiosulphate:                        2Mn(OH)3(s)   +   2I-(aq)   +   6H+(aq)   â†Â Â  2Mn2+(aq)   +   I2(aq)   +   6H2O(l)                          I2(aq)   +   2S2O32-(aq)   â†Â Â  2I-(aq)   +   S4O62-(aq) Chemicals           weewee sample, MnSO4, conc.

H2SO4, alkaline KI, standard Na2S2O3, starch solution Apparatus          titration apparatus, pipette, 250cm3 volumetric flaskfulful x2, beaker, droppers, magnetic stirrer, white tile Procedure          1.> bundle up a water sample with two 250cm3 volumetric flasks. regain to fill the flasks completely with water without trapping any denudate bubbles.          2.> To one of the volumetric flask, priming coat round 1 cm3 of MnSO4 solution well below the anaesthetize with a dropper.          3.> Similarly, introduce about 1 cm3 of alkaline KI solution to the same flask. Be sure that no airmanship becomes entrapped and then invert the stopped                flask to distribute the precipitate uniformly.          4.> When the precipitates has...If you fatality to get a upright essay, order it on our website: Ordercustompaper.com

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