Transcript Gas Variables POGIL

GAS VARIABLES POGIL
Proportionality

Directly Proportional
 As
𝑦

one increases, so does the other
=𝑘∗𝑥
Inversely Proportional
 As
𝑦
one increases, the other decreases
=
𝑘
𝑥
Thermodynamic Observables

Aspects of a system that we can observe, measure, or
calculate in some way.

Pressure – P
kilopascals (kPa)

Temperature – T
Kelvin (K)

Volume – V
Liters (L)

moles – n
(number of molecules)
moles
Gas Variables POGIL

Stop After Question 11
Bell: 1/14
 Warm-up
 Answer

Week # 2
at the front
on bell sheet
Objective:
I
can describe how the gas variables relate to one
another.
Announcements

SAGE interim testing
 All
next week
 Bring Head Phones
Review: Question 3

Which gas variables is most closely related to the
length of arrows in model 1?
Review: Question 6

Two factors that influence the pressure of a gas:
 1:
 2:

How do these effect the pressure of a gas?
Review: Question 11
Experiment A
(Adding More Gas)
Direct or Inverse?
Algebraic Expression
Experiment B
(Heating the Gas)
Gas Variables POGIL

Stop after Question 16
Question 12b

What is always true for the external and internal
pressure of a gas in a flexible container?
Question 16

Provide a molecular level explanation for the
increase in volume among the balloons in
experiment E.
Gas Variables POGIL

Stop after Question 21
Key Concept: Question 20
Experiment C
Experiment D
(Adding More Gas) (Heating the Gas)
Direct or Inverse?
Algebraic
Expression
Experiment E
(Reducing the
external pressure)
Gas Laws
Boyle’s Law
Charles’ Law
Gay-Lussac’s Law
Avagadro’s Law
𝑘
𝑉=
𝑃
𝑉 = 𝑘𝑇
𝑃 = 𝑘𝑇
𝑉 = 𝑘𝑛
Combined Gas Law:
𝑃𝑉
𝑇
=𝑘
Quick Quiz

A gas is kept in a non-flexible container.
 What
would happen to the gases pressure if the volume
of the container is decreased?
 What
would happen to the gases temperature if the
pressure were to be increased?
Using the Gas Laws
Combined Gas Law:
𝑃𝑉
𝑇
=𝑘

Step 1: List all knowns and unknowns

Step 2: make two combined gas laws

Step 3: make the two gas laws equal

Step 4: Plug and Chug
Example:


A gas in a 500 ml non-flexible container is heated
from a temperature of 20 K to a temperature of 30
K. If the pressure of the gas was originally 50 kPa,
what is the new pressure of the gas?
Step 1: List knowns and unknowns

Step 2: make two combined gas laws

Step 3: make the two gas laws equal

Step 4: Plug and Chug
Example:


A gas in a non-flexible container with a volume of 1
L is cooled from a temperature of 50 K to a
temperature of 45 K. What is the new volume of
the gas?
Step 1: List knowns and unknowns

Step 2: make two combined gas laws

Step 3: make the two gas laws equal

Step 4: Plug and Chug
Gas Laws Worksheet

Due Friday