Exp053

Dominican University student project

Urea Chemspider ID 1143 Methanol Chemspider ID 854 Average solubility is 20.1471 g/ 100 grams Average molarity is 2.6555 M
 * Name || Classification || Molecular Formula || SMILES ||
 * Urea || Amide || (NH2)2CO || NC(=O)N ||
 * Methanol || Alcohol || CH3OH || CO ||
 * Procedure:**

1. Weigh 5.100 grams of urea on Acculab scale. 2. Measure 20 mL of methanol and added to 125 mL Erlenmeyer flask 3. Add urea to the methanol in doses of roughly .5 grams per time. Mix thoroughly after each addition. 4. Continue to add the urea to the solution until the urea will not dissolve anymore. 5. Weigh the remaining unused amount of urea and subtract that number from the original amount used. This is now the amount of solute that is in the solution. 6. Pour the solution into four small test tubes that fit the centrifuge. 7. Place the tubes into the centrifuge and let it run for 3 minutes. 8. Remove the test tubes and place into test tube rack. 9. Weigh empty evaporation vials and label them 1-4. 10. Remove the solution from the tubes by using a pipette or dropper. Measure volume that was extracted by placing it into a 10mL graduated cylinder. Record this value and place solution into each vial. 11. Weigh the vial and solution on the scale and record the volume. 12. Place the vials in a hot water bath until they have a dry, white, crystalline, substance appear. 13. Once the vials have cooled off, weigh the vials on the scale and record the data. 14. Wait 10 minutes and reweigh the vials to compare the data. If data is changing allow the vials to dry longer in the hood for 4 days and reweigh.

Solute: Urea Amount used: 3.390 grams Solvent: Methanol Amount used: 20 mL Solvent Density: .7919 g/cm3
 * Results:**

Solubility 1 13.655 grams- 12.857 grams= .798 grams/ 5.0mL=.1596 2 13.642 grams -12.844 grams=.798 grams/5.1 mL =.1565 3 13.570 grams-12.892 grams=. 688 grams/4.3 mL=.160 4 13.634 grams-12.824 grams=.810 grams/5.0 mL=.162 Molarity 1. .798 g/ 60.07 amu= .0133 moles/ .005 L= 2.657 M 2. .798 g/60.07 amu=.0133 moles/.0051 L=2.605 M 3. .688 g/60.07 amu=.0115moles/.0043 L=2.663 M 4. .810 g/60.07 amu= .0135 moles/ .005 L=2.697 M Molality 1. .7918 * 5.0mL=3.959 grams/1000=.003959 kg .0133 moles/.003959kg=3.359 2. .7918* 5.1 mL=4.038 grams/1000=.004038 kg .0133 moles/.004038kg=3.294 3. .7918* 4.3 mL=3.405 grams/1000=.003405 kg .0115 moles/.003405kg=3.377 4. .7918 *5.0 mL=3.959 grams/1000=.003959 kg .0135 moles/.003959kg=3.410
 * || Empty Vessel || Volume of Solution || Mass of Vessel+ Solution || Mass of Vessel + Solute ||
 * Vial 1 || 12.857 grams || 5.0 mL || 16.957 grams || 13.655 grams ||
 * Vial 2 || 12.844 grams || 5.1 mL || 16.992 grams || 13.642 grams ||
 * Vial 3 || 12.892 grams || 4.3 mL || 16.407 grams || 13.570 grams ||
 * Vial 4 || 12.824 grams || 5.0 mL || 16.951 grams || 13.634 grams ||
 * || Solubility g/mL || Concentration moles/L || Molality moles/kg || Solubility g/100g ||
 * Vial 1 || .1596 || 2.657 M || 3.359 || 20.1566 grams ||
 * Vial 2 || .1565 || 2.605 M || 3.294 || 19.7651 grams ||
 * Vial 3 || .160 || 2.663 M || 3.377 || 20.2071 grams ||
 * Vial 4 || .162 || 2.697 M || 3.410 || 20.4597 grams ||

Solubility per 100 grams .7918* X= 100 grams of methanol so 126.2945 mL is 100 grams 1. .1596 g/mL*126.2945 mL=20.1566 grams/100 grams 2. .1565 g/mL*126.2945 mL=19.7651 grams/100 grams 3. .160 g/mL * 126.2945 mL=20.2071 grams/100 grams 4. .162 g/mL*126.2945 mL=20.4597 grams/100 grams