Dominican University student project
01/25/09 Bart Leszczynski

[Removed from SolubilitySum spreadsheet because only collecting non-aqueous solvents JCB]

Chemical Information
Solute
Citric Acid monohydrate
Solute SMILES
"O=C(O)CC(O)(C(=O)O)CC(=O)O.O"
Solute Type
Carboxylic Acid
Solute link to ChemSpider
chemspider.com/Chemical-Structure.305.html
Solvent
Water
Solvent SMILES
O
Solvent Density
0.998g/ml

Procedure

  1. Obtain 20g of Citric Acid monohydrate and 16ml of water.
  2. Use a 250ml beaker as a mixing vessel.
  3. Pour the water into the beaker and keep adding 1g portions of Citric Acid monohydrate until precipitate forms. Mix periodically by swirling the solution in order to dissolve all solute.
  4. Transfer the saturated solution into four centrifuge tubes (4ml each). Centrifuge for 5 minutes.
  5. Calibrate the balance and obtain the mass of four 25ml vials (to be used as evaporation vessels).
  6. Decant the liquid portion of the centrifuged material into a clean 10ml graduated cylinder and measure the obtained volume (pipettes may be used for a more accurate volume measurement) for all four centrifuge tubes.
  7. Transfer the saturated solution from the graduated cylinder into a tared vial (4ml each) and measure the mass.
  8. Place the four vials containing the saturated solution directly on the hot plate in order to evaporate the solvent. Avoid boiling the solution too vigorously (it is best not to exceed 100oC which is the boiling point of water). The saturated solutions may be left over night to evaporate.
  9. Allow the evaporation vessel to cool once the evaporation is complete.
  10. Measure the mass of the evaporating vessel and all its contents.

Experimental Data:
Mass of Empty Evaporation Vessel (g)


Mass of Evaporation Vessel + Solution (g)

Trail 1 (vessel 1)
21.436
Trail 2 (vessel 2)
21.119
Trail 3 (vessel 3)
21.384
Trail 4 (vessel 4)
19.048
*Calculated using the density of water, volume of solution, and the final mass of solute.

Mass of Evaporation Vessel + Solute (g)

Trail 1 (vessel 1)
16.147
Trail 2 (vessel 2)
16.129
Trail 3 (vessel 3)
16.594
Trail 4 (vessel 4)
15.355

Volume of Solution (ml)

Trail 1 (vessel 1)
5.3
Trail 2 (vessel 2)
5.0
Trail 3 (vessel 3)
4.8
Trail 4 (vessel 4)
3.7

Solubility (g solute recovered/ml solution)

Trail 1 (vessel 1)
0.633
Trail 2 (vessel 2)
0.664
Trail 3 (vessel 3)
0.790
Trail 4 (vessel 4)
0.672
Average
0.690

Molarity (mol solute/L solution)

Trail 1 (vessel 1)
3.012
Trail 2 (vessel 2)
3.160
Trail 3 (vessel 3)
3.759
Trail 4 (vessel 4)
3.198
Average
3.282

Molality (mol solute/kg solution)

Trail 1 (vessel 1)
3.019
Trail 2 (vessel 2)
3.162
Trail 3 (vessel 3)
3.758
Trail 4 (vessel 4)
3.197
Average
3.284

Solubility (g solute/100g solution)

Trail 1 (vessel 1)
38.81
Trail 2 (vessel 2)
39.97
Trail 3 (vessel 3)
44.12
Trail 4 (vessel 4)
40.23
Average
40.78

Calculations:

Solubility (g solute recovered/ml solution)

Trial 1: (3.355g) / (5.3ml) = 0.633 g/ml

Molarity (mol solute/L solution)

Trial 1: (1mol/210.14g of Citric Acid monohydrate) * (1000ml/L) * (0.633g/ml) =
= 3.012 mol/L

Molality (mol solute/kg solution)

Trial 1: (0.998g/ml) * (kg/1000g) * (5.3ml solvent) = 0.0053 kg solvent

(3.355g solute recovered) * (mol/210.14g) = 0.016 mol Citric Acid monohydrate

(0.016mol Citric Acid monohydrate) / (0.0053kg solvent) = 3.019 mol/kg

Solubility (g solute/100g solution)

Trial 1:

(3.355g solute recovered) / (21.436g solution – 12.792g evaporation vessel) * 100 =

= 38.81 g solute / 100g solution