Spring Break Chemistry -A Webquest

Spring Break Chemistry -A WebQuest

At long last it's Spring Break! You and your friends plan to spend your time off basking in the sun at the beach. All thoughts of chemistry are banished from your mind. Or are they? How does that sunscreen work? How do your new shades darken automatically? Why do the grains of sand in your sand castle stick together? Your teacher is always saying, "Chemistry is everywhere!” Could he be right? Could chemistry actually intrude on your Spring Break? Complete the WebQuest and find out!

Tan Without the Sun! What makes self-tanning solutions work? Click on the following link to find out.

http://pubs.acs.org/cen/whatstuff/stuff.html

1. What is the active ingredient in self-tanning products and what source do companies use to obtain this chemical?

2. Often, discoveries in science are made by “accident”. Explain how the effects of DHA on the skin were discovered.

3. Name and describe the chemical reaction that causes the skin to turn brown.

4. Do artificial tans protect you from the burning rays of the sun? Why or why not?

Don’t go for the burn! Use Sunscreen! If the “tan in a can” does not appeal to you, hit the beach to get some color. Don’t forget your sunscreen. Understanding how sunscreen works can help you to use it more effectively. Go to the site below to find out more! http://www.sfsu.edu/~shs/skinclinic/sunscreen.htm

5. The action of sunscreen may be either physical or chemical. Explain the difference between the two regarding their contents and how they work.

6. Is a tanning bed a safer alternative than the beach? Why or why not?

In the Shade As you lie on the beach, a cloud suddenly masks the sun. Luckily, the sunglasses you are wearing are photochromic and they lighten automatically. Could chemistry have anything to do with this? Of course! Go to the site below and scroll down to the section on Photochromic Sunglasses.

http://www.howstuffworks.com/sunglass4.htm

7. What molecules are the photochromic lenses coated with and how do they cause darkening?

8. Under what circumstances might the photochromic lens not react to light?

Castle Chemistry What could be more fun than building a castle in the sand? The only thing that could make it better is understanding the chemistry behind the structure. Click on the link below to find out why sand “sticks”.

http://www.firstscience.com/SITE/ARTICLES/sandcastle.asp 9. What causes sand particles to stick together when water is added?

10. What problem is created if the sand is too wet?

11. How does the science of sand castles relate to earthquakes?

Keeping Your Suit On! Lycra is the miracle fabric of the century. It helps keep the stretch in your swimsuit and adds durability to delicate fabrics. Find out more at:

http://pubs.acs.org/cen/whatstuff/stuff.html

12. Lycra is actually just a trade name for a fiber that has been around for many years called:

13. In what ways is Lycra superior to rubber thread?

14. After reading about Lycra/spandex, what one property of the polymer do you think is most important when the fiber is used in swimsuits and why?

15. The article mentions some future potential uses for Lycra/Spandex. Suggest at least two other possible uses of your own.

Pause for Refreshment! You’ve been baking in the hot sun for hours. It's time for a soda and a snack. Rumors about junk food abound. Does soda really rot your teeth? Can chocolate make you happy? Do Pop Rocks really explode in your mouth? Check out the links below and investigate these rumors. Pop Rocks Candy Pop Rocks candy feels like it explodes in your mouth when you eat it. In fact it sort of does explode. To find out what makes the “POP!” in Pop Rocks, go to:

http://www.howstuffworks.com/question114.htm

16. When making hard candy, the ingredients are heated to a boil then to 300 o F. What is the purpose in heating the candy to this extreme?

17. What might the candy be like if it were not heated long enough or to a high enough temperature?

18. Explain why Pop Rocks pop!

Sweet Chemistry: Chocolate Have you ever craved a chocolate bar when you were down? Can chocolate really make the blues go away? Find out more at: http://chemistry.about.com/library/weekly/aa090301a.htm http://chemistry.about.com/gi/dynamic/offsite.htm? site=http://faculty.washington.edu/chudler/choco.html

19. Chemicals in chocolate can elevate your mood and have even been compared to certain illegal drugs. What are these chemicals and how are they different in their interactions with the human body than the illegal drugs that they have been compared to? 20. You have probably heard that chocolate can make your dog very ill. What chemical in chocolate is harmful to dogs and why?

A Chemical Brew It’s hot! You want something cool and refreshing. How about an ice cream float? Did you know that a float is practically a chemical laboratory? Check out the ice cream at the link:

http://pubs.acs.org/cen/whatstuff/stuff/8245icecream.html

21. The ice cream in your float is actually a colloid. What is a colloid and is it homogeneous or heterogeneous?

22. A colligative property is when the addition of a solute to a solvent alters the boiling point or freezing point of a solvent. This property is in effect both in the manufacture of ice cream and in the ice cream itself. Explain.

Do Things Really Go Better with Coke? When you were young, perhaps you tried to dissolve a chicken bone, tooth, or egg shell in Coke. What gives Coke this ability? Read on. http://antoine.frostburg.edu/chem/senese/101/consumer/faq/why-phosphoric-acid-in-soda- pop.shtml

23. What acid is added to soda pop and why is it added?

24. What acids are found in fruit drinks?