Molecular Structure Lab Report: Determining Polarity Instructions: For this investigative phenomenon, you will investigate why certain substances, such as oil and vinegar, don't mix. To do so, you will combine various compounds, compare their solubility, and determine their polarity. Fill in each section of this lab report and submit it to your instructor for grading.
Objective(s):

Hypothesis:
Create a hypothesis that predicts the polarity of iodine solution, vinegar, vegetable oil, salt, water, and rubbing alcohol.
Materials
deionized (distilled) water
rubbing alcohol
vegetable oil
iodine solution
sodium chloride (salt)
acetic acid (vinegar)
test tubes or clear plastic cups
tablespoon and teaspoon
stirring sticks
permanent marker for labeling

Controlled variables:
Independent Variable:
Dependent Variable:
Summary of Steps:
Using the steps for predicting the polarity of compounds, determine the polarity of water (H2O). Place your answers in table one. Once you have successfully predicted the polarity of water, you will be able to determine the polarity of the other compounds using steps two through five of the experiment.
Put about 2 tablespoons of deionized water into each of two labeled test tubes or clear cups. Add about 2 tablespoons of rubbing alcohol to one cup and 2 tablespoons of iodine solution to the other. Mix the contents with a stirring stick. In table two, indicate whether the solutes (vinegar and iodine solution) are soluble in the solvent (water). Then conclude whether the compound is polar, nonpolar, or ionic. (Hint: Like substances dissolve like substances, and polar solvents dissolve ionic compounds.)
Put about 2 tablespoons of vegetable oil into each of two labeled test tubes or clear cups. Add about 2 tablespoons of rubbing alcohol to one cup and 1 teaspoon of salt to the other. Mix the contents with a stirring stick. In table two, indicate whether the solutes (rubbing alcohol and salt) are soluble in the solvent (vegetable oil). Then conclude whether the compound is polar, nonpolar, or ionic.
Put about 2 tablespoons of rubbing alcohol into each of two labeled test tubes or clear cups. Add about 2 tablespoons of water to one cup and 2 tablespoons of vinegar to the other. Mix the contents with a stirring stick. In table two, indicate whether the solutes (water and vinegar) are soluble in the solvent (rubbing alcohol). Then conclude whether the compound is polar, nonpolar, or ionic.
Put about 2 tablespoons of vinegar into each of two labeled test tubes or clear cups. Add about 2 tablespoons of iodine solution to one cup and 2 tablespoons of vegetable oil to the other. Mix the contents with a stirring stick. In table two, indicate whether the solutes (iodine solution and vegetable oil) are soluble in the solvent (vinegar). Then conclude whether the compound is polar, nonpolar, or ionic.
Data:
Table 1:
Reference the VSEPR geometry chart and the electronegativity chart from the lesson to fill in the table below.

Compound: H20.
Lewis structure:
The difference in electronegativity of each bond:
VSEPR sketch:
Polar, nonpolar, or ionic?
Molecular shape:
VSEPR electron geometry:

Table 2:
(Hint: Like substances dissolve like substances, and polar solvents dissolve ionic compounds.)
Solute | Solvent | Soluble or insoluble? | Is the solute polar, nonpolar, or ionic? | Is the solvent polar, nonpolar, or ionic? |
Vinegar | Water |
Iodine solution | Water |
Rubbing alcohol | Vegetable oil |
Salt | Vegetable oil |
Water | Rubbing alcohol
Vinegar | Rubbing alcohol |
Iodine solution | Vinegar |
Vegetable oil | Vinegar |
Conclusion
Write a conclusion statement that addresses the following questions:
Explain how you determined the polarity of all your compounds by first predicting the polarity of water, and then mixing different solutes and solvents to find the polarities of the other substances.
Which of your polarity and solubility predictions were correct?
How do you think the investigation can be explored further?
Post-Lab Reflection Questions
Answer the reflection questions using what you have learned from the lesson and your experimental data. It will be helpful to refer to your chemistry journal notes. Answer questions in complete sentences.
Were any of your substances difficult to identify as polar, nonpolar, or ionic? Explain.

How do models help scientists predict the polarity of molecules?