Study Buddy Unit 2: Energy and States of Matter (STATES)
Terms
Compressibility
Pressure
Temperature
Energy
Kinetic Molecular
Theory (KMT)
Ideal Gas
Description
Symbol
Unit
A measure of how much the volume of matter decreases under
pressure.
Results from the force exerted by a gas per unit
P
mmHg,
surface area of an object
atm, kPa
°C, K
A measure of the average kinetic energy of
T
particles in matter
The capacity for doing work or producing heat
J, cal
Joule,
calorie
Assumes gas particles: 1. Do not attract or repel, 2. Are spread out 3.
Are constantly moving, 4. Have elastic collisions.
A theoretical gas that perfectly follows the gas laws at all conditions of
pressure and temperature
Representations:
Solid
Liquid
Gas
Particle Model
Attraction
between particles
Space between
particles
Shape
Volume
Compressibility
High
Medium
Low
a. particles do not attract
or repel
no forces shown
Low; packed
tightly
Definite
Medium
High; lots of
space
Indefinite
b. particles are spread out
lots of space between
Definite or
fixed
Almost none
Definite or
fixed
Almost
none
Indefinite
Indefinite
Easily
compressed
Why are gases more easily compressed than solids or liquids?
Gases have an indefinite shape and volume because there is so much
space between the particles. Gas particles can compress easier
because of the empty space between the particles.
Identify the particle diagrams below as showing kinetic or
potential energy. Then, explain which in each pair is showing
higher energy and why.
A.
B.
Kinetic energy. The left
diagram shows larger arrows,
which indicates faster motion
and more KE.
9/2/15
Draw gas particles in the balloon that
show the KMT properties. In a few
words, tell how each is shown.
Potential energy. The right
diagram shows more space
between the particles, which
indicates the particles are
further apart and have more
energy due to their position
and thus more PE.
c. particles are constantly
moving
shown by arrows
d. particles have elastic collisions
when they hit each other, particles
bounce off
On each SCUBA tank, draw and explain
these terms and what particles would
have to do to increase each variable:
1. temperature
Temp. is a measurement of
average kinetic energy, so
higher temperature is shown
by particles moving faster
(longer arrows).
2. pressure
Pressure is caused by
particles hitting the sides of
the container and bouncing
off. Higher pressure is caused
by particles hitting the container more
frequently or with more force.
SCIE_CHEM_STATES_MAT_STUDYBUDDYTE_AL
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1
Gas Pressure, Volume, Temperature, and number of Moles Relationships
Look at each gas situation below. Then, determine the change in the missing pressure, volume or
temperature.
Before
After
Before
After
Before
After
Before
After
Before
After
Before
After
Before
After
Gas Laws
*Make sure to use your STAAR Chemistry Reference Materials*
Value with Units
0°C and 1 atm
Standard Temperature
and Pressure (STP)
Volume of ideal gas at
STP
Kelvin conversion
Pressure conversion
Ideal gas constant (R)
22.4 L/mol
0°C = 273 K or K = °C+273
1 atm = 760 mmHg = 101.3 kPa
0.0821 L*atm/mol*K (or others)
For each pair of variables, draw a line representing
their relationship and label as direct or inverse.
P
P
V
Inverse
9/2/15
P
n
V
T
Direct
Direct
V
T
n
Direct
Direc
What volume at STP do 2.00 moles of Oxygen
gas (O2) occupy? Show all work in your
calculations.
T = 0°C = 273K
P = 1 atm
n = 2.00 mol
PV = nRT
(1 atm)(V)=(2 mol)(0.0821 L*atm/mol*K)(273K)
V = 44.8 L
Does your answer make sense? Why?
This answer makes sense because 1 mole of
an ideal gas at STP is 22.4 L, so 2 moles
should be double 22.4, which is 44.8 L.
SCIE_CHEM_STATES_MAT_STUDYBUDDYTE_AL
copyright © CFISD 2015
2