LEARNING HUB connecting Science curricula to everyday applications with LESSON PLANS, lab aids and more
Your One STOP Science source
In collaboration with Washington International School Team Science
​
***GREEN WRITING = info about the website construction
Chemistry 12: Gas Laws Pressure Law
Joseph Louis Gay-Lussac
Pressure Law
Gay-Lussac's Law
Ideal gases
Prior Knowledge/Preview
Balloons--the type you travel in
​
VIDEO Gay-Lussac's pressure law with data Washington International School
​
Aerospace CONNECTIONS:
Gas Laws in aerospace
Applications and examples:
Fuels--temperatures
Breathing in Space--pressure/ temperature in a space capsule
Balloons in Space
More about balloons
In the Gas Laws, we are investigating the relationships between P, V and T
​
Start by studying the relationship between TWO variables at a time and keeping the third constant as well as the amount (# moles) of gas
What is kept constant in Gay-Lussac's pressure law?
Gay-Lussac's Pressure Law
​
Data analysis activity
​
To investigate the relationship between pressure and temperature in gases. The volume has to remain constant as well as the amount of gas (number of moles of gas).
​
You need a vessel with a fixed volume to hold a fixed mass of gas, a means to heat it and a pressure gauge
Collect the data here in the table--LEAVE the fourth, right-hand column empty
​
For each trial, write the temperature of the equipment and gas in the data table
Process your data:
Look at the results table and write a statement that describes how the temperature affects the pressure of the gas
​
And draw a graph of the data
Processing your data:
The graph does not go through the origin--so NOT a direct proportional relationship between pressure and temperature
​
So extrapolate (extend) the line of your graph backwards so it cuts the x-axis. The is the NEW origin--with the 0 temperature being Absolute Zero
Gay-Lussac's Law:
The pressure of a fixed mass of gas is directly proportional to the absolute temperature provided that the volume is kept constant
Gay-Lussac developed the law of Combing Gases which sates:
When gases react, they do so in volumes which are in simple, whole number ratio and to the volume(s) of the product, if it is a gas.
​
It starts by applying Avogadro's Law relating the number of moles to volumes of each gas. The number of moles of gases in a reaction is given by the coefficients in the balanced equation.
