03:- To Find The pH Of Given Samples
Aim:- To determine the pH of given sample.
Requirement:- Sample, beaker, beret, beaker, chemical and indicator etc.
Procedure :- First we added 10 gm of soil in a beaker then we added 25 ml distal water in beaker and kept it for about 5 minutes. Then we started machine to take the reading, first we calibrated the pH by using chemical from bottle no. 1 then placed the pH rod in soil and took the reading of the sample.
Observation :- In pH machine the reading of soil is mostly upto 6.5 – 7.5.
Conclusion :- By this we can check several samples pH
1. Tap water
2. Distal water
4. Lemon etc.
04:- Chemical oxygen demand
Aim :– To take COD of given samples
Requirement:- Test-tube, Pipit, Beaker, Conical flask, Weight machine, Funnel.
Procedure:-First take three test-tube , keep one as blank other two for samples. To take COD of the samples first add stones in the test-tube, then take mercury sulphate about 0.4 gm, then add 40 ml distal water in blank in second and third add 20 ml distal water .
Then add 0.25 N ( potassium dichromate) about 10 ml and S2HO4 about 30 ml in sample as well as in blank. Then give a oil bath for 2 hours about 150 degree celcious, took 500 ml flask added the sample one drop of ferrous solution in flask. We added ammonium sulphate in the beret , then tit-rate till the color of the sample changes and took the reading by the formula.
FORMULA: COD= (blank-sample) X 0.255 X 8000
Observation :- Blank = 9.5
Grey water = 17.5 – 9.5= 8
Azolla = 27.1 – 17.5= 9.3