Weekly Web Work #2:
Physical versus Chemical Change
This assignment was due by noon on Tuesday, January 21, 2003.
Submissions are no longer accepted.
Please type your last name, first name:
Please type your last five digits of your ID number:
Please type a nickname: (in case your answer gets used in class).
In lecture on Wednesday, physical and chemical changes of matter were discussed briefly. These were also discussed in recitation. Here is an old exam question on this subject. How might you approach answering this question? The original question and multiple choice answers are in black and the thought processes used to answer the question are in blue.
Which of the following is a chemical property (or change)?
In everyday language we talk about mixing. Sometimes mixing produces mixtures. Other times mixing results in a chemical reaction. How can we tell? If a chemical reaction happened, new substances form and and we may see a change in color, bubbles indicating the formation of a gas, or other tell-tale signs. Here, simpling passing a magnet near the sample would separate the iron and iron oxide, so the iron and the iron oxide were chemically unchanged. E is not the correct answer.
Now it is your turn. Tell me if each of the following is a chemical or a physical change and justify your answer by telling me your thought process.
You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT button at the bottom of this page.
Question 1. Burning aspirin produces carbon dioxide and water vapor.
Explain your choice.
Question 2. Aspirin tablets are made by pressing together starch and aspirin.
Questions 3. A sidewalk is formed when concrete sets (hardens).
Remember, since this file is in the archive, you can no longer submit it.
This site is made possible by funding from the National Science Foundation (DUE-9981111). ©2003, S. Holladay & K. Anliker/ IUPUI, all rights reserved.