2.2 Modifications:
- Lab manual stated that only “plastic” lab ware be used in the experiment, but instead, glass was used during the laboratory experiment and not all plastic.
- The sample of magnesium salts were not transferred with washings.
3. Experimental Results:
3.1 Determination of Magnesium Using an EDTA Titration.
Data Table:
3.2 Calculations:
Trial 1: Vol. EDTA=19.45mL
(0.4mmol/mL) * 19.45 = .778mmol
7.78 * (10-4)mol * 24.31 g/mol
= .001891g
(.001891g/.1514) * 100 = 1.249%
Trial 2: (0.4mmol/mL) * 18.95 = .758mmol
7.58 * (10-4)mol * 24.31 g/mol
= 0.01842698
(0.01842698 g/.1516) * 100 = 1.215%
Trial 3: (0.4mmol/mL) * 18.95 = .758mmol
7.58 * (10-4)mol * 24.31 g/mol
= 0.01842698
(0.01842698 g/.1513) * 100 = 1.217%
4. Discussions:
4.1 Error Analysis:
- When titrating the solution into the Erlenmeyer flask, there could be excessive EDTA released into the flask of salts, resulting in an inaccurate reading of the titration.
- Inaccurate reading of EDTA in the buret could alter the results of the experiment.
5. Conclusion:
During this experiment, investigators were able to titrate each trial and become within 2.5+/- % of each other. The titration was determined by equilibrium when the solution turned from a light pink to blue. At this point the titration was complete, and the result was a faint blue. The experiment was determined to be successful due to the % range of each trial. All data prepared was in agreement with one another, and the mass of magnesium was able to be determined.
