REQUIREMENTS:
- Measuring cylinder
- Funnel and filter paper
- Spectrophotometer
CHEMICAL REQUIRED:
- Stannous chloride
- Ammonium molybdale
- Distilled water
THEORY:
Controlled concentration of phosphorus in water is critical for a stable ecosystem amount of phosphorus in order to survive. However, excess phosphorus leads to eutrophication the over enrichment of a water body with nutrients.
The EPA water quality criteria recommend a maximum phosphorous concentration of 100 Hg/C in river and streams and 25Hg/C in lakes in order to prevent eutrophication from occurring. Inorder to inhibit corrasion of pipes a thin layer of phosphorous builds on the inside of the pipes.
The phosphorous cycle is a simple method to comprehensive the role of phosphorous that play in environment since phosphorous has limited method to ender vapour form phosphorous is essential to various biological compounds in organism death, the organic phosphorous taken up by organism.
PROCEDURE:
At first the sample water was taken from the botanical pond of Trichandra Multiple Campus. 50ml of water sample was taken and then it was filtered. 2ml of ammonium was added. 5 dr5ops of stannous chloride was added and it was turned into blue color. It was left for 10 min and was observed with.
OBSERVATION TABLE:
| Concentration (x) | Absorbance (y) |
| 0.1 | 0.125 |
| 0.2 | 0.230 |
| 0.3 | 0.388 |
| 0.4 | 0.5 |
| 0.5 | 0.573 |
| 0.6 | 0.595 |
| 0.7 | 0.729 |
| 0.8 | 0.763 |
| 0.9 | 0.793 |
| 1.0 | 0.912 |
CALCULATION:
Dilution factor(D.F) = 10+40/10
= 50/10
= 5
From the graph, we get
(x1,y1) = (0.1,0.1)
(x,y) = (0.4,0.4)
now,
y-y1 = y2-y1/x2-x1 (x-x1)
y-0.1=0-3/0-3 (x-0.1)
y=x-0.1+0.1
y=x
But from MS–Sccel 2013
y=0.8247x+0.1072 equation (1)
Comparing equation,
y=mx+c
m=0.8247
c=0.1072
y= mx+c
or, 0.232=o.8247x+0.1072
or, x=0.232-0.1072/0.8247
or, x= 0.1248/0.8247
= 0.1513 mg/l
CONCLUSION:
Obtained concentration of phosphate in given water sample indicates slightly higher amount than drinking standard and household use.