Mixed Gas Law
Calculations
• Objectives:
• Today I will be able to:
• Apply Boyle, Charles, Gay-Lussac, Combined, Ideal, and
Dalton’s gas law to solving problems
• Informal assessment – monitoring student interactions and
questions as they complete the practice problems
• Formal assessment – analyzing student responses to the
practice problems and exit ticket
• Common Core Connection
• Make sense of problems and persevere in solving them
• Reason abstractly and quantitatively
Lesson Sequence
• Evaluate: Warm – Up
• Explain: Dalton’s Law
• Elaborate: Dalton’s Law Practice
• Elaborate: Mixed Gas Law Problems
• Evaluate: Exit Ticket
Warm - Up
• Carbon dioxide gas occupies a volume of 200
ml at STP. What is the density of the gas?
• How do I know when to use the combined gas
law, ideal gas law and graham’s law to solve
problems?
Objectives
• Today I will be able to:
• Apply Boyle, Charles, Gay-Lussac, Combined,
Ideal and Dalton’s gas law to solving problems
Homework
• Finish practice problems
Agenda
• Warm Up
• Mixed Homework Review
• Ideal Gas Law
• Ideal Gas Law Practice
• Dalton’s Law Notes
• Dalton’s Law Practice
• Exit Ticket
Mixed Gas Law
Homework
Lets look over the homework together!
Kinetic Molecular Theory,
Ideal Gas Law
Kinetic Molecular Theory
of Gases
• Gases consist of small particles, either atoms
or molecules, that have mass
• Gas particles must be separated from each
other by relatively large distances
- While gases do have volume, that volume is
considered to be zero, which is why we say the
volume of a gases’ container is the volume of
the gas
Kinetic Molecular Theory
of Gases
• Gas particles must be in constant, straight-line,
rapid motion
- Explains why when you spray a bottle of
perfume at one end of the room, the people at
the other end are able to smell it right away
- Gases diffuse rapidly
Kinetic Molecular Theory
of Gases
• Gases exert pressure because their particles
collide with the walls of the container
-Think about blowing up a balloon – the balloon
blows up evenly because gas particles are
hitting all points of the inside walls the same
Kinetic Molecular Theory
of Gases
• Gas particles exert no force on one another –
they neither attract or repel
- It is true enough for our class
Kinetic Molecular Theory
of Gases
• Gas particles may collide with each other, but
these collisions are assumed to be elastic
- Think about playing pool – you transfer
kinetic energy from your stick to the cue ball
to make it move
Kinetic Molecular Theory
of Gases
• The average kinetic energy of the gas particles
depends on the temperature of the gas
- Gas particles do not all have the same kinetic
energy – some move slowly and some move
very fast, but most are in between
Elastic
Inelastic
Kinetic Molecular Theory
of Gases
• A gas that obeys all these “rules” is called an
Ideal Gas
• No gas will obey all the “rules,” but some are
close enough
• Nonpolar gases at high temperatures and low
pressure are very close
Ideal Gas Law
PV = nRT
P = pressure
V = volume (use only L)
n = number of moles of gas
R = constant (.0821 atm-L/mol-K or 62.4 mmHgL/mol-K)
T = temperature in Kelvin
Ideal Gas Law
Practice
Complete the practice at your desk!
Dalton’s Law
Dalton’s Law of Partial
Pressures
• The sum of the pressures of all gases present
in a system equals the total pressure of the
system
P1 + P2 + P3 + … = Pt
Dalton’s Law Practice
Complete the practice at your desk. If you have
questions, please ask Mr. Klotz. We will review
selected problems
Exit Ticket
• Which problem was most challenging on the
worksheet
• What strategies did you use to determine
which gas law you needed to use to solve the
problem?