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Experiment 1

Titration curves (set 1 of 2)

Calculating titration endpoint volume

Used the colorimeter titration program to find the endpoint and corresponding EDTA volume. 
experimental ppm = EDTA vol (uL)/sample vol (mL)
Sample volume = 2 mL


 ppm CaCO3
Endpoint EDTA 
volume (uL)
 Trial 1
 Endpoint EDTA 
volume (uL)
Trial 2
 Avergage Endpoint EDTA volume (uL) Experimental CaCO3 ppm
 10 ppm 35.4130.29 32.85  16.43 ppm 
 25 ppm 64.7160.38  62.55  31.28 ppm 
 50 ppm 105.51108.70 107.11  53.55 ppm 
 75 ppm 172.00 169.67 170.84 85.42 ppm 
 100 ppm 205.13 209.26 207.20 103.6 ppm 
 125 ppm 254.92 257.86 256.39 128.20 ppm 
 150 ppm 300.17 310.82 305.50 152.75 ppm 
 175 ppm 369.55 368.24 368.90 184.45 ppm 
 200 ppm 429.61 425.82 427.72 213.86 ppm


Plotting the expected endpoint volume versus experimental endpoint volume:

Conclusion

Experimental data pretty close to the expected data. Consistently higher than theoretical. Could probably be improved by taking more data points around the endpoint.   
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