chemistry111 lap

Name TA

Determination of phosphate in Naturar waters Post Lab Questions

1. Recorded Absorbance data

Test tube # Concentration Absorbance 1 0.0 ppm 0.00 2 0.05 ppm 3 0.10ppm 4 0.20 ppm 5. 0.50 ppm 6. 1.00 ppm 7. Unknown

2. Cte.ate an Excel graph of concentration versus absorption that contains a linear trendline, an equation for the trendline, and an Rf value for the trendline. Attach the data and graph to this worksheet.

l. Insertlh€ the slope and y-intercept from your equation and the absorbance of your unknown into the following equation and determine the concentration ofphosphate in your unknown water sample.

Concentration (ppm): absorbance - y-intercept (b,) Slope (m)

4. concentration of phosphate in your unknown water sample

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