- Molarity Of Edta 0 009433m Burette Reading Trial 1 2 3 Trial 4 Final Reading 17 994l 16 20 Ml 32 20 Ml Initial Re 1 (572.52 KiB) Viewed 52 times
eluent of 25.00 mL of the diluted sea water. Note: this is the
moles of H+ displaced by the Na+ , Ca 2+ and Mg 2+ cations.
2.Report the average titration value of the 25.00 mL diluted sea
water with EDTA
Use the EDTA titre to calculate the number of moles of Ca 2+ and
Mg 2+ ions present in 25.00 mL dilute sea water. The ratio of
magnesium to calcium ions in sea water is known to be close to 5:1.
Using this ratio, calculate the number of moles of each. moles of
both Ca 2+ and Mg 2+: moles of Mg 2+ :
moles of Ca 2+:
3.From the difference between the moles of H+ displaced from the
resin and the total moles of H + displaced by Ca2+ and Mg2+
calculate the number of moles of Na+ in the dilute sea water.
4.Calculate the concentrations (mol/L) for each cation in the
original (undiluted) sea water
Molarity of EDTA 0.009433M Burette reading Trial # 1 # 2 # 3 Trial #4 Final reading 17.994L 16.20 mL 32.20 ml Initial reading 12.00 ml 0.20ml 16.20 mL Volume EDTA used 15.99 wh 16.00ml 16.00ml Average of closest three titrations within 0.10 mL 15.99 mL Volume of unknown sea water used to prepare dilute sea water 25.00mL Total volume of dilute sea water prepared 250.0mL UNCERTAINTIES: 25 mL pipette + 0.03 250 mL volumetric flask + 0.12 DETERMINATION OF THE TOTAL CATION CONCENTRATION: Table 1.1 Titration of an eluted 25.00 ml aliquot of diluted sea water with standardized sodium hydroxide Molarity of NaOHOOS Burette reading Trial Trial #3 Trial # 4 Final reading Trial # 1 #2 18.21 m2 37.58 ml 1.67 mL 22.00 mL 15.54 mL Is szal Initial reading Volume NaOH used Average of closest three titrations within 0.10 mL 15.56 mL Uncertainty in the volume of NaOH added + 0.04