Explaining Physical Properties with Bonding
Use what you know about intermolecular forces to explain the following situations.
1. a) How does the density of metal compare to the density of water?
b) If you fill a shallow Petri dish or cup with water and place a paper clip on top,
the paper clip will float. Why? Try to explain using what you know about bonds.
2. Research the boiling point of water. How does it compare to other liquids (example: H2S)? Why is it so much higher or lower?
3. a) Why does ice float on water? How do hydrogen bonds play a role?
b) In ecological terms, what is the impact of this phenomenon?
4. Water is often regarded as the universal solvent. Why is water so good at dissolving so many substances?
5. What is the role of hydrogen bonding in proteins? How does hydrogen bonding affect the shape?
6. Cut a strip of plastic and rub it with something wooly. Turn on a tap so there is a small, steady flow of water. What happens when you bring the strip close to the stream? Why does this happen? What do you suppose would happen if you did the same thing but with a stream of vegetable oil (non-polar substance)?
Bonus: What is the role of hydrogen bonding in plant life? Consider how plants “absorb” water through the roots. Can you explain this?
Please note that this assignment is due on Monday, November 24, 2008. You are encouraged to share your assignment through google docs (by 8AM on the morning of November 24) or if you wrote your answers, it is due at the beginning of class.