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Lam Gary Experiment #1: Investigating Solubility and Acid-Base Reactions Purpose: The purpose of this experiment is to understand the solubility of compounds and how acid-base properties affect solubility. Results: See attached pages for tables regarding the results of the experiment. Discussion: In part 1, diethyl ether is relatively non-polar and miscible with hexane, which is also non-polar. Dichloromethane is polar, but non-polar enough to mix with hexane. Ethanol, ethyl acetate, and water are all polar which makes them immiscible with hexane. With acetone, there should be layering because it is polar and hexane is nonpolar but our experimental data said the resulting solution was fully miscible. This error could have been caused by observing the solution incorrectly. In part 2, diethyl ether and toluene are relatively non-polar which makes them immiscible with polar water. Dichloromethane is polar but not polar enough to mix with water. Acetone and ethane are polar, which makes them miscible with water. With ethyl acetate, there should not be layering because it is polar and water is polar but our experimental data said the resulting solution was fully miscible. This error could have been caused by observing the solution incorrectly. In part 3, the solutions of ethanol and water and 1-propanol and water were miscible but 1-butanol and 1-pentanol were not miscible with water. This is because alcohols are miscible with water if they contain less than 4 carbon atoms in the backbone. Increased size of they alkyl group disrupts the hydrogen-bonding network and the induced dipole-induced dipole forces are decreased. In part 4, we mixed benzoic acid and water, heated the solution, and then let the solution cool. Before heating, benzoic acid did not dissolve in the water because benzoic acid is not polar enough to in dissolve water at room temperature. After heating, the benzoic acid dissolved in the water and formed white crystals. Heating increases solubility because the increased temperature and the entropy term contributed more to the free energy equation, pushing delta G to become negative. After cooling, the solution stayed mostly the same because the temperature decrease has little effect on the solution. In part 5, we mixed benzoic acid and water with five different solutions. NaOH and NH4Cl dissolved the benzoic acid because an acid-base reaction occurs. Cooling and adding HCl caused benzoic acid to reform because HCl replaced benzoic acid in the reaction because HCl is a stronger acid. NaHCO3 dissolved benzoic acid and gas formed in clear liquid. HCl didn't react with benzoic acid because they are both acids. Benzoic acid dissolved in diethyl ether and when the ether evaporated on the watch glass, it left behind solid benzoic acid. In part 6, diisobutylamine and water were not miscible because water is polar and diisobutylamine is not. NaOH did not react because both NaOH and diisobutylamine are bases. Adding HCl caused an acid-base reaction. Diethyl ether was miscible in the diisobutylamine but not the water because diethyl ether is non-polar. In part 7, the solution from part 4 dissolved with the addition of diisobutylamine because of an acid-base reaction and after 6 drops the solution was saturated so no more diisobutylamine could be dissolved into the solution. Conclusion: 1,2-dichloroethane is non-polar and dissolves in hexane but not water. Dibromomethane is non-polar and doesn't dissolve in water. Methanol is polar and dissolves in water. 1,4-butanediol is too big and won't dissolve in water (see alcohol). I learned how solubility and acid-base reactions affect solubility by predicting solubility. ... View Full Document

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