Gas Laws Lesson 6
11.15 & 16 Chemistry Boon
Objective
Catalyst
 I can state Avogadro’s Law
and the combined gas law
and use them to solve gas
law problems.
 What gas law was
demonstrated by the can
crush demonstration? Why?
 What gas law was
Agenda
 Catalyst
 The Combined Gas Law
 Avogadro’s Law
 Gas Law Poster Project
 Exit Slip = Complete Poster
demonstrated by the
marshmallow video? Why?
Gas Laws Mini-Review
Gay-Lussac’s Law: At constant volume, pressure
and temperature are ____________
proportional.
directly
For example, as pressure increases, temperature
_________.
increases
Charles’s Law: At constant pressure, volume and
temperature are ____________
proportional. For
directly
example, as volume increases, temperature
_________.
increases
Boyle’s Law: At constant temperature, volume and
pressure are _______________
proportional. For
inversely
example, as volume increases, pressure
___________________.
decreases
https://www.youtube.com/watch?v=Mytvt0wlZK8&feature=related
The Combined Gas Law
 The combined gas law combines Gay-Lussac’s Law,
Charles’s Law, and Boyle’s Law into one.
 If you are given any five of the variables, you can solve
for the sixth.
Think, Pair, Share: Why do we
need the combined law? What
new situation does it address?
 Example 1:
 P1=300 torr, P2=900 torr, V1=40
L, V2= 10 L, T1=250 K T2=???
 Example 2: A cheetohs bag is sitting in a car at STP and
has a volume of .5 L. Then, the car is heated to 27 °C.
The pressure increases to 1.2 atm. What is the bag’s new
volume?
 Example 3: If a gas at 6 L and 30 torr is compressed to a
pressure of 600 torr, what is the new volume of gas?
Avogadro’s Law
https://www.youtube.com/watch?v=GlZ5wxejWy8&feature=endscreen
 In 1811, Italian scientist Amadeo Avogadro found that
equal volumes of all gases, under the same conditions,
have the same number of particles.
Specifically, at standard
temperature and pressure,
one mole of any gas has a
volume of 22.4 L.
Avogadro’s Law
 Avogadro’s law means that gas volume is directly
proportional to the number of moles of gas at the
same temperature and pressure.
 Example 1: V1 = 22.4 L, n1 = 1 mol, V2
= ___ , n2 = 5 mol
 Example 2: What is the volume of 10
mol of nitrogen gas at STP?
 Example 3: 6 mol of ammonia gas has
a volume of 120 L. At the same
temperature and pressure, what is the
volume of 18 mol of ammonia?
Gas Law Poster
 Due at end of class
 Poster must contain:






Name of gas law
Definition
Graph
Equation
Example problem
Answer the example problem on
the back of your poster.