Boiling Point of Water
Names: _____________________
Student worksheet to accompany wiki-chem lab
_____________________
Pre-Lab Questions
A) Describe in your own words the cause of boiling.
B) When water boils, what are the bubbles composed of?
C) Do you think that you are about to waste a class period watching water boil?
Wiki Page: Introduction
D) What happens to the pressure in the bell jar in the video?
E) Why does the water boil when the vacuum pump is turned on?
F) What happens to the temperature of the water?
G) What is the explanation provided for the change in temperature?
Wiki Page: Prediction
H) What is the temperature that you predict your water sample will boil at?
Wiki Page: Collecting the Data
I) How will you know when the water sample has reached its boiling point?
J) What do you expect the graph to look like when the water is boiling? Sketch the
basic shape of the graph you expect. [ Be honest, don’t wait until the end ☺ ]
K) What was the temperature that your water sample boiled at?
Wiki Page: Class Data
L) Calculate the average boiling temperature of each of the classes. Record the
average boiling temperature along with the atmospheric pressure in the table
below.
Class Average Boiling
Temperature (°C)
Atmospheric
Pressure (mmHg)
Altitude
(ft)
Lutz Period 1
Lutz Period 2
Deets Period 1
Deets Period 2
Wiki Page: Using Your Graphs
M) Based upon the boiling temperature of water at Yellowstone Lake, what was the
atmospheric pressure that day?
N) Based upon the boiling temperature of water on top of Grand Teton, what was the
atmospheric pressure?
O) At what temperature would you expect water to boil in Lutz, Florida? (elevation
62 feet... yes it is a real city!!!)
P) According to your data will water boil at 100°C at sea level?
Q) Using the slope formula and the data presented, at what temperature would you
expect water to boil at Death Valley? (elevation -282 feet ... that's below sea
level)
SHOW YOUR WORK
Wiki Page: Conclusion
R) Explain the relationship between temperature and pressure related to boiling point
in your own words.
S) Read and restate the proper definition of boiling point found at
http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/vappre.html#c4
T) Why are there high altitude cooking instructions on many prepackaged foods?
Make sure to staple your 2 graphs to this worksheet before you turn it in.