Exp199

=Researcher= Jianbo Zhao =Objective= The objective of this experiment is to determine the solubility of Benzoic acid in methanol, chlorofrom and hexane. =Procedure= Set up three tubes which have three solutions. First, measure three pure solvent and then measure those density of solutions. =Results= [|The measurements]
 * [Some of these are impossible - you mixed up numbers in the sheet JCB]**
 * Solvent || Average Measured Concentration (M) ||
 * methanol || 15.31 ||
 * chloroform || 20.418 ||
 * hexane || 0.272 ||




 * Pic.1 Put three sealed tubes into water bath set as 41C**




 * Pic.2 Bath for 1 hour and take them out.**




 * Pic.3 Bath three tubes into water at room temperature**



=Discussion=
 * Pic. 4 Measure three density into different volume of flasks**
 * 1) Due to the experiment, chloroform solve a lot into solute. And hexane is the second more solve into solute. Methonal is the third.
 * 2) During the experiment, the hexane benzoic acid solution's concentration is much less than those two solutions.

=Conclusion=
 * 1) The concentration of methanol, chloroform and hexane in benzoic acid solution is 15.31M, 20.41M and 0.272M at room temperature.**[wording incorrect (and spelling) JCB]**
 * 2) The concentration of hexane in benzoic acid is much less comparing to other two solutions.

=Log=

Date: Jan. 25th, 2011
12:45 Find 3 new tubes. Put Bezoic acid into each tube. Labeled them as A, B and C. Calculate the mass and put in around 4g. Measured each mass. 13:09 Started to measure pure solvents. Hexane. methanol and chloroform with different volume of flasks, which is 10ml, 5ml, 2ml, 1ml. 14:05 Set up water bath to 40C 14:07 Put in different solvent in each tube. Added up to three quarters of the whole tube. 14:17 Sealed the tubes and put them into a beam for water bath. 14:50 The actual temperature wento to 41C. Put three sealed tubes into a beam **[do you mean beaker? JCB]** and put it into the water bath. Take **Picture.1** 15:50 Take three tubes out. See the crystal above in tube 3. Lots of crystal in tube 1 which is hexane solvent. Little saturation in Chloroform solvent solution. Take **Picture.2** **[Did you take the temperature at this point? From the image I don't think that bath would last very long at 40C JCB]Yes, it was 40C at that point. Actually the temperature of the liquid in the beam is the same as the liquid in water bath.-James** 15;53 Transfer three clear liquid to three new tubes, marked as A1 B1 and C1. **[Did you have trouble getting a clear solution from the chloroform sample? It floats so how did you avoid transferring over some solid? JCB]** 15:59 Take a beam and put water inside, then bath three tubes. Recorded the water temperature which is 14C, take **Picture.3** **[Are you sure 14C? JCB] Yes, I measured it.** 16:07 Take them out and started to measure the density of each solution with various volume of flasks. Take **Picture.4** **[Did you see solid come out after it started to cool? 8 min is probably not enough time to equilibrate - also 14C is very far from room temp - 25C is where the second bath should be JCB]**