Transcript Ideal Gas Laws

Ideal Gas Laws
1. What causes gas pressure in a
closed container?
2. What factors effect the pressure
of an enclosed gas?
Day 1: What is an Ideal Gas?
• No gas behaves exactly like an ideal gas but it is a good
model for making predictions.
• The Kinetic Theory of Matter (all matter is made of tiny,
moving particles) explains the behavior of gasses.
• An ideal gas:
1. Particles in a gas are in constant and random motion.
2. The motion of one particle is unaffected by another
unless they collide.
3. Forces of attraction among particles can be ignored
under ordinary conditions.
Day 1: Gas and Pressure
• Pressure is the result of force distributed over
an area.
• Collisions between particles of a gas and the
walls of the container cause the pressure in a
closed container.
• The more frequent the collisions, the greater
the pressure of the gas.
Day 2: Factors That Effect Pressure
increase
1. Temperature of a gas will ____________ its
pressure.
Reducing the volume of a gas will increase
2. __________
its pressure
3. Increasing
_________ the number of particles in a gas
will increase the pressure of the gas.
Day 2: Problem
1. Use the diagram below to determine how
much does pressure goes up when the volume
is decreased by one-half? One-Third?
Day 2: Answer
1. When volume decrease by one-half pressure
increase by two times.
2. When volume decrease by one-third pressure
increases by 3/2 times. (Inverse relationship)
Day 3: Gas Laws
• Charles Law states that the volume of a gas is directly
proportional to its temperature, when pressure and the
number of particles in a gas is held constant.
• Boyle’s Law states that the volume of a gas is inversely
proportional to its pressure when temperature and the
number of particles is held constant
P 1V 1 = P2V 2
Day 3: Combined Gas Law
• Combined Gas Law (where n = the number of
gas particles.)
Day 3: Problems
Use the Gas Laws to graph the following relationships.
Pressure
Volume
Temperature
Volume
Day 4: Review
• 1. Use the kinetic theory of matter to explain why the
pressure of a gas increases when its temperature increases?
• 2. If temperature doubles what happens to volume if
everything else stays constant? Which of the gas laws applies
in this case?
• 3. If volume doubles what happens to pressure if everything
else stays constant? Which of the gas laws do you use in this
case?
• 4. If the number of particles doubles in a gas what happens to
the pressure? Which law did you use?
Day 4: Answers
• 1. As the molecules or atoms in the gas are
heated they move faster, spread out and collide
more often with the sides of the container
increasing the pressure on the container.
• 2. According to Charles's Law temperature
volume will double if temperature doubles.
• 3. According to Boyle’s Law pressure will
decrease by half if volume doubles.
• 4. The pressure will double according to the
Combined Gas Law.
Day 5: Quiz (Pressure!)