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Introductory Chemistry Homework
For many of the questions below you will need to refer to a periodic table:
1. Compare and contrast a major similarity and difference between polar covalent bonds
and ionic bonds. It may help to define them before listing a similarity and difference.
2. Define both ionic and hydrogen bonds, and state a similarity between ionic bonds and
hydrogen bonds. Explain the similarity, and the reason behind the similarity.
3. Can you draw the structure of potassium chloride (KCl) and methane (CH4) by just
looking at a periodic table? What kind of bonds are formed? Are these polar or nonpolar? Why?
4. In C2H4, how many bonds are between the two carbons? 1? 2? 3? Why? What is the
molecular mass of C2H4? How do the protons, neutrons, and electrons from each atom
contribute to that mass? You will need to refer to a periodic table.
5. Write a summary describing why each of the following properties of water can be
attributed to its polarity. In addition to defining each, you must explain how the
polarity of water (and hydrogen bonds) plays a role. Please keep the bullet point format
in your response.
Water's activity as a solvent
Different states of water
Water's specific heat capacity
Waters heat of vaporization
Water's cohesive and adhesive properties
6. Watch the following video: https://www.youtube.com/watch?v=uXaP43Zbz7U. Draw
the structure of PTFE (Teflon) including the sharing of electrons (covalent bonds). Why
do the atoms of PTFE (Teflon) not react with other substances (i.e. “non-stick”). Think
about where fluorine is in the periodic table.
7. Don’t forget to complete the attached Properties of Water Case Study!
Experiment # Experiment Name Detalis of how the experiment was conducted
Plastic and Glass
What property of water explains the results? Why?
• Play the video of an experiment being performed.
• Fill out the attached worksheet for every experiment.
• Details of how the experiment was conducted
• Experimental Results
• What property of water explains the results? Explain why.
What are some of the properties of water?
• Found in different states
• Polar/Hydrogen bonds
• Specific Heat Capacity
• Heat of Vaporization
Experiment #1 – Pepper, Water, and Soap
Experiment #2 – Blooming Flower
Experiment #3 – Water Balloon
Balloon Filled with Air
Balloon Filled with Water
Experiment #4 – Ethanol Dissolving
Hint: Experiment #4 – Ethanol Dissolving
Experiment #5: Water on glass and plastic
• At 10:00am I emptied the dishwasher. I noticed several plates were
still wet, so I set them out to dry. Some of the plates were plastic,
whereas others were glass.
• At 11:00am I noticed that all of the glass plates were dry, whereas the
plastic plates were still wet. How could this be?
• Hint: The strength of adhesion is stronger between water and glass
than water and plastic (glass is more polar).