Ideal Gas Law
Kyle Baseden
Chemistry I
Gas Laws/Ideal Gas Law
C.5.2 Using the ideal gas equation of state PV = nRT, calculate the change in one variable when
another variable is changed and the others are held constant.
CCSS.MATH.CONTENT.HSA.SSE.A.1.A-Interpret parts of an expression, such as terms, factors,
and coefficients.
1. Materials
 Whiteboard
 Projector
 Projector screen
 Dry erase markers
 Worksheet
2. Objective(s)
 Calculate the pressure, volume, amount of gas, or temperature of an ideal gas at one
particular state.
 Calculate the change in one of the variables in the ideal gas law.
 Understand what an ideal gas is.
 Understand the difference between an ideal gas and a real gas.
3. Motivation
 The instructor should have an active review over all of the gas laws with the students.
o Students should respond with the mathematical representation of each gas law.
o Gas laws
 Boyle’s Law
 P1V1=P2V2
 Charles’ Law
 V1/T1=V2/T2
 Gay-Lussac’s law
 P1/T1=P2/T2
 Avogadro’s law
 n1/V1=n2/V2
o Have a discussion in which it is explained that each of
these equations are proportions that must always equal a
constant value.
o Can set each proportion equal to the same constant.
 This leads to the ideal gas law when the equations
are rearranged.
4. Goal for Learner
 Students should be able to recognize and use the ideal gas law while also knowing the
difference between ideal and real gases.
5. Content and Procedures
 After having the discussion over how the ideal gas came about, the instructor should go
over what each of the variables in the ideal gas law are.
Revised 4/11
o P is the pressure
 Should be in atmosphere
o V is the volume
 Should be in Liters
o n is the number of moles of the gas
 is in moles
o R is the universal gas constant
 Is a constant
 Always 0.08206 Latm/(molK)
o T is the temperature in Kelvin
 This equation was determined experimentally and works for gases that behave ideally.
o These types of gases are called ideal gases.
 Real gases act as ideal gases under low pressures and high temperatures.
 The pressure should be under 1 atmosphere.
o For the purposes of this course you should assume that the gases we discuss
behave ideally unless stated otherwise.
 The instructor should then go over some example problems that are given in the
PowerPoint notes.
6. Practice/Application
 After giving the lecture and notes and practice problems, students will receive the
worksheet they are to complete over concepts and questions over the ideal gas law.
 Students will work on the worksheet as a homework assignment and will be given time to
work on the worksheet if time allows.
o The students will turn in the worksheet to be graded for correctness by the
beginning of the next lesson.
7. Evaluation of student learning
 The instructor should make full use of formal and informal evaluations to gauge student
understanding and comprehension of the topic.
o Formal
 The worksheet the students complete and turn in will be graded for
correctness.
 The worksheet should be turned in by the students by the beginning of the
next lesson.
 The results of the formal evaluation will be used to guide future
lesson plans.
o If students need more practice with the concept of the ideal
gas equation, a review of the topics can occur again if the
students need it.
o Informal
 During the lecture portion of the lesson
 The instructor should ask probing questions during the lesson to
make sure students have gained a good understanding of the
material covered in the lecture.
o Example
 When calculating a change in a variable of an ideal
gas, how can the ideal gas law be rearranged to
solve for the necessary change.
 During the extra time to work after the lesson
Revised 4/11


The instructor should monitor the work students are doing by
walking around the classroom and assisting students if they need
extra instruction.
If many students are having difficulties with a problem, the
instructor can go over the problem as a whole class to ensure
students understand the concepts.
8. Closure
 After giving the lecture, the instructor should provide an active review of the major
concepts of the lesson.
o The instructor should review what the equation used to determine one of the
factors of an ideal gas is.
 PV=nRT
 The instructor should review what the variables mean
 P is pressure
 V is volume
 n is the number of moles of the gas
 R is the universal gas constant
o Is always 0.08206 Latm/(molK)
 T is the temperature of the gas
o This equation only works for an ideal gas.
 Ideal gases act as though there are no interactions between particles
 In reality there are some interactions between the individual
particles that comprise the gas.
Revised 4/11