Mr. B’s Blogspot

Seventh grade science teacher, Ms. Wright, helped her students discover how air bags work. Students learned a variety of facts about air bags, and then conducted an experiment to test their home-made air bags. The crash test dummy for this experiment was a raw egg.

Here are some of the learning objectives for the unit:

1. Acetic acid reacts with sodium bicarbonate to produce a gas. 
2. Acetic acid and sodium bicarbonate are the chemical names for vinegar and baking soda, respectively.
3. The two main purposes of an air bag are to slow a person’s forward movement into the steering wheel (or dashboard) and to provide a cushion between the person and the steering wheel (or dashboard). 
4. The three parts of an air bag are the bag itself, the sensors, and the inflation system (or gas generator). 
5. The main chemical responsible for the inflation of an air bag is sodium azide, which rapidly decomposes into nitrogen gas and sodium metal when it is ignited.
6. Other reactions occurring within an air bag ensure that highly reactive, dangerous byproducts are changed into stable and safe compounds.
7. The inflation of an air bag and the other chemical reactions occur in a very short amount of time (1/25^th of a second).
8. The reaction between acetic acid and sodium bicarbonate is similar to the decomposition of sodium azide because both reactions produce a gas.
9.