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Report Lab #1: Investigating Solubility and Acid-Base Reactions Purpose: The purpose is to understand the solubility of polar and non-polar solutions and how acid-base properties affect this solubility. Discussions: In part 1, diethyl ether is miscible with hexane and is therefore non-polar. This is because hexane is a non-polar solvent. The rest of our results show that ethyl acetate, acetone, ethanol, and dichloromethane are miscible as well. However, all of these solutes are polar and should have been immiscible and formed layers. Dichloromethane is an exception since it is non-polar enough to mix with hexane and become miscible. It's possible that the solutions were not observed properly or not enough solute was added. The resulting solution of hexane and water formed white precipitate and is therefore immiscible (4B). In part 2, ethyl acetate, acetone, and ethanol are polar solutes, so they should be miscible with water and create a clear solution. However, our results show that ethyl acetate formed a clear layer on top making it immiscible (5T). Again, this error could be due to improper observation or lack of mixing the solution. Diethyl ether and toluene are non-polar, so they turned out to be immiscible with water. Dichloromethane is polar but also holds some non-polar qualities which does not mix with polar water. A clear layer formed on the bottom of the test tube (5M). Part 3 shows that ethanol and 1-propanol are miscible with water. 1-butanol and 1pentanol are not miscible with water since a layer forms on top and bubbles form in between the layers (6M). Only alcohols that contain less than 4 carbon atoms in the backbone are miscible with water. This is because the hydrogen bonds become disrupted past 1-propanol and the intermolecular forces decrease. In part 4, benzoic acid, a white, powdery solid is mixed in water and heated to boiling point. Initially, benzoic acid sinks to the bottom of water and is immiscible. This is because benzoic acid is not polar at the starting room temperature. At 170C very small bubbles form, but benzoic acid remains the same. Boiling finally occurs at 235C (7M). Benzoic acid formed white crystal precipitate in the water. So, solubility depends on temperature in this case. Part 5 dealt with the solubility of acids. Water, benzoic acid, and five different solutes were mixed. When NaOH was benzoic added, acid dissolved. However, after cooling and adding HCl, it reappears on top and the tube is mildly warm. This occurs because HCl is a stronger acid and took the place of benzoic acid in the reaction. NH4OH had no reaction with benzoic acid. The same happens with HCl and NaHCO3, which caused the benzoic acid to float to the top (8M). In the case of diethyl ether, a layer formed on top. After removing ether onto a watch glass, a solid layer of white benzoic acid was left behind as the ether evaporated. In part 6, diisobutylamine and water were mixed with three solutes. When NaOH was added, diisobutylamine floated on top and was immiscible (9T) because they are both bases. The same happened with diethyl ether because it is non-polar. HCl started an acid-base reaction with bubbles and was miscible. In part 7, the benzoic acid solution showed no change after 3 drops of diisobutylamine were added. After 3 more drops were added, a small layer formed on top. The layer increased after adding the last 3 drops since the solution was already saturated. Conclusion: Based on the data collected in this experiment, 1,2-dichloroethane will dissolve in hexane but is immiscible in water because the solute is non-polar. Dibromomethane is also immiscible in water because it is non-polar. Methanol is miscible with water since it is polar. 1,4-butanedial contains too many carbon atoms as an alcohol and does not mix with water. This lab taught us that like dissolves like. So, a non-polar solvent will mix well with non-polar solutes, and a polar solvent will mix well with polar solutes. There are exceptions, such as with dichloromethane and hexane. Also, the solubility of benzoic acid and water depends on temperature Questions: 1. For each term, provide the structure of two molecules used in this experiment. a. polar protic b. polar aprotic 2. Provide the structure of two organic molecules used in this experiment that, in their pure states, interact mainly through induced dipole-induced dipole forces. 3a. When 157 mg of dipentylamine was added to 122 mg of benzoic acid and 2 mL of water, a completely homogenous solution was formed. Draw the structures of the species present in the water 3b. When 1.57 grams of dipentylamine was added to 122 mg of benzoic acid and 2 mL of water, two distinct liquid layers were observed. Explain. ... View Full Document

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