In this experiment you will compare the physical properties of some common covalent compounds and how they are related to a compounds structure

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In this experiment you will compare the physical properties of some common covalent compounds and how they are related to a compounds structure. In particular, you will investigate the effects of intermolecular forces on a compounds properties. You will also gain experience using the PubChem database (links provided in the tables).

1. Using data from the PubChem database and what you have learned in general chemistry complete the following table. Where more than one value for a measurement has been determined choose the smaller value. Table 1: Compound Lewis Structure Molar Mass (g/mol) 1,4-dichlorobenzene Aspirin Naphthalene Urea * Round your answer to the nearest whole degree. ** If less than 1 mg/mL record as < 1 mg/mL. Melting Point (oC)* Polar or NonPolar? Solubility in water (mg/mL)** 2. According to the data in Table 1 do polar or non-polar compounds tend to have higher melting points? Provide an explanation for this observation in terms of intermolecular forces between the molecules. 3. According to the data in Table 1 do polar or non-polar compounds tend to have higher solubility in water? Provide an explanation for this observation in terms of intermolecular forces between the molecules. 4. Cyclohexane is a non-polar compound that is a liquid at room temperature. Which compounds in Table 1 would you predict to have good solubility in cyclohexane? Which would have poor solubility in cyclohexane? Explain your choices in terms of the intermolecular forces between the molecules. 5. Use the data provided on the PubChem website each of the following compounds to complete the table below. The 3D Conformer and chemical and physical properties of each substance will be especially useful. Note that 1 centipoise (cP) = 1 mPas. Table 2: Compound Glycerol Hexane Water 1-decanol Lewis Structure Viscosity (cP) Longest continuous chain of atoms Number of oxygen atoms Hydrogen bonding capacity? 6. Which of the molecules in Table 2 would you expect to have the strongest dispersion forces? Explain how you arrived at your answer? 7. Which of the molecules in Table 2 would you expect to have the highest surface tension? Explain how you arrived at your answer? 8. According to the data in Table 2 does hydrogen bonding increase or decrease a liquids viscosity? Provide an explanation for this observation in terms of intermolecular forces between the molecules. 9. Complete the following Table. Table 3: Compound Acetic acid Lewis Structure Iso-propyl alcohol Water 10. Vinegar is predominantly a mixture of water and acetic acid, rubbing alcohol is almost pure iso-propyl alcohol and orange juice is mostly water. Using this information and the data in Table 3 explain the results in this video https://www.youtube.com/watch?v=HVmpDLFGRno in terms of the intermolecular forces present (you may need to copy and paste the link into your browser). 11. Chemists use databases such as PubChem to search for data about chemical compounds. Why is this database preferred over a crowdsourced website such as Wikipedia?