文档介绍：The purpose and requirements of the experiment
Grasp the method of chromium ion determination and the usage of spectrophotometer.
Be able to drawing standard curve and use the standard curve method to get the experimental result.
Realize the toxicity of chromium ion and remember to wash one’s hands immediately after finishing the experiment.
Know international standard and other standards so as to know the pollution degree of water.
Experimental program
Experimental drugs and instruments
Reagents :(1 :1) sulfuric acid ()
(1 :1) phosphoric acid()
Hydrogen zinc oxide solution
Chromogenic reagent (DPC)
More than 50ml industrial wastewater
hexavalent chromium solution(10mg/l)
Instruments:Spectrophotometer, Beaker, filter paper, pipette and funnel
More than 12 clear colorimetric tubes (include 50ml and 100ml)with plugs
Experimental steps
The preparation of different concentration chromium standard solution: decant 10 ml chromium standard into a 100ml colorimetric tube, then dilute the liquid to that respectively take 0ml, 1ml, 2ml, 4ml, 6ml, 8ml and 10ml water from the tube to eight 50ml colorimetric tube and dilute to 50ml. Decant ml (1 :1) sulfuric acid and (1 :1) phosphoric acid to each tube and shake them. Lastly add 2ml DPC into the each tube and make sure the liquid is shaken up. Lay aside them for 5 to 10 minutes.
The preparation of in