Exp054

Dominican University student project 01/30/09 Pedro Vallejo

// Solute and Solvent Data // **[Value marked as DONOTUSE because so low [|compared to rest] - poor mixing likely cause JCB]** 1. Keep adding solute until no more solute can be dissolved. 2. Add saturated solution to centrifuge tube. Centrifuge for five minutes. 3. Decant into a clean 10mL graduated cylinder and measure the volume of saturated solution. 4. Obtain a 25mL beaker as the evaporation vessel. Record the mass of this evaporation vessel. 5. Pour the saturated solution into the evaporation vessel and record its mass. 6. Prepare a hot water bath and evaporate the solvent from the saturated solution. Be aware of the temperature as one does not want to melt the solute while the solute is evaporating. Do not go 5°C past ethanol’s boiling point which is 78.4°C. 7. Leave the remaining solute to sit for 5 minutes. Record the mass of remaining solute and evaporation vessel. 8. Repeat this whole process 4 times. // Table 1 – Chemical Information // (per experiment) || 5.0mL || · Mass of 50mL evaporation vessel 1: 30.548g · Mass of 50mL evaporation vessel 2: 26.286g // Table 2 // – //Mass of Evaporation Vessel + Solution Before evaporation// *For experiment 1, the mass of the evaporation vessel and solution was taken after it had been in the hot water bath for about a minute.
 * Solute || Succinic Acid ||
 * Solute SMILES || OC(CCC(O)=O)=O ||
 * Solute Type || Carboxylic Acid ||
 * Chemspider link of solute || http://www.chemspider.com/1078 ||
 * Solvent || Ethanol ||
 * Solvent SMILES || CCO ||
 * (average) solubility g/100g || 1.08 ||
 * (average) concentration in moles/liter || 0.0593 ||
 * Procedure **
 * ** Solute ** || ** Succinic Acid ** ||
 * Solvent || Ethanol ||
 * Solvent density || 0.789 g/mL ||
 * Volume of solution
 * ** Trial ** || ** Mass (g) ** ||
 * Experiment 1 with vessel 1 || 33.159 ||
 * Experiment 2 with vessel 2 || 28.817 ||
 * Experiment 3 with vessel 1 || 34.159 ||
 * Experiment 4 with vessel 2 || 29.774 ||

// Table 3 – Mass of Evaporation Vessel + Solute // // Table 4 – Mass of Solute Obtained //
 * ** Trial ** || ** Mass (g) ** ||
 * Experiment 1 with vessel 1 || 30.573 ||
 * Experiment 2 with vessel 2 || 26.306 ||
 * Experiment 3 with vessel 1 || 30.584 ||
 * Experiment 4 with vessel 2 || 26.345 ||
 * ** Trial ** || ** Mass (g) ** ||
 * Experiment 1 with vessel 1 || 30.573-30.548 = 0.025 ||
 * Experiment 2 with vessel 2 || 26.306-26.286 =0.02 ||
 * Experiment 3 with vessel 1 || 30.584-30.548 = 0.036 ||
 * Experiment 4 with vessel 2 || 26.345-26.286 = 0.059 ||

// Table 5 – Solubility g/mL using volume of solution // Sample calculation – Experiment 1 0.025g/5.0mL = 0.005g/mL // Table 6 – Concentration in M (moles/liter) // Molar mass of Succid Acid: **118.09 g/mol** Sample calculation – Experiment 1 (0.005g/mL) * (1000mL/1L) * (1mole/118.09g) = 0.0423 moles/liter // Table 7 – Molality in moles/kg using mass of solution // Density of Solvent: 0.789g/mL Kg of solvent: (0.789g/mL) * (5.0mL) * (1kg/1000g) = 3.945g Ethanol or 0.003945kg Ethanol
 * Calculations **
 * ** Trial ** || ** Solubility (g/mL) **  ||
 * Experiment 1 || 0.005 ||
 * Experiment 2 || 0.004 ||
 * Experiment 3 || 0.0072 ||
 * Experiment 4 || 0.0118 ||
 * ** Trial ** || ** Concentration (moles/liter) **  ||
 * Experiment 1 || 0.0423 ||
 * Experiment 2 || 0.0339 ||
 * Experiment 3 || 0.0610 ||
 * Experiment 4 || 0.0999 ||
 * ** Trial ** || ** Molality (moles [solute]/kg [solvent]) **  ||
 * Experiment 1 || 0.0537 ||
 * Experiment 2 || 0.0429 ||
 * Experiment 3 || 0.0773 ||
 * Experiment 4 || 0.127 ||

Moles of solute Sample calculation – Experiment 1 (0.025g) * (1 mole/118.09g) = 2.12 X 10-4 moles Succinic Acid (2.12 X 10-4 moles Succinic Acid)/(0.003945 kg Ethanol) = 0.0537g Succinic Acid/Kg Ethanol // Table 8 – Solubility g/100g solvent using mass solution // Sample calculation – experiment 1
 * ** Trial ** || ** Solubility (g/100g) **  ||
 * Experiment 1 || 0.957 ||
 * Experiment 2 || 0.790 ||
 * Experiment 3 || 0.900 ||
 * Experiment 4 || 1.69 ||

(0.025g mass of solute/[33.159g – 30.548g]) *100 = 0.957 g solute/ 100 g solution