“Cooking Under Pressure” by Chen, Anderson, & Wang Page 1
Ling Chen, Science Department, Borough of Manhattan Community College
Jennifer Y. Anderson, Health Science, Nursing, Brookdale Community College
Diane R. Wang, Biology, Plant Breeding and Genetics, Cornell University
In this story, concepts such as vapor and external pressures, boiling point, the ideal gas law, and chemical reaction rates are emphasized.
Cooking Under Pressure: Applying the Ideal Gas Law in the Kitchen
It is 6 p.m. and the Clarksons are preparing dinner for their friends, Carol and Steve. Ben is a truck driver and has been taking some night classes at a local community college for enrichment. Ann also leads a busy life, working two jobs. She has decided that tonight, in the interest of time, to try out the new pressure cooker she recently received for her birthday.
Ann: Honey, our guests are going to be here soon! Will you taste the beef stew? Let me know what you think so I can whip up a dessert quickly.
Ben: Yes, boss. Hmm … defi nitely under-cooked. Carol and Steve won’t like that.
Ann: What? How come? Th e pressure cooker should cook food faster.
Ben: Did you forget to use the vent stopper?
Ann: Shoot, I sure did. What does it do anyway?
Ben: Do you really want to know? I just learned about the gas laws in my chem class, very interesting stuff .
Ann: Sure, tell me more about it.
Ben: All right. As you know, water normally boils at 100°c, so the temperature of water can’t exceed 100°c in an open vessel (like what’s used in conventional cooking). Under normal conditions (1 atmosphere external pressure at sea level), any food in water can’t be cooked at temperatures greater than 100°c. However, the boiling point of water varies with external pressures—water boils at a higher temperature