Chemistry
Chapter 14.3
“Ideal
Gases”
I. Ideal Gas Law
A. Review…
1. Combined Gas Law – uses 3 variables
*assume that ________
Moles of gas does not change.
B. New Variables…
1. n = number of moles of gas
2. R = ideal gas constant
-how did we get it?
R = (P x V) / (T x n)
(101.3 kPa x 22.4 L) / (273 K x 1 mol) = ?
R = 8.31
C. New Equation…
P xV = n x R xT
Practice Problems…
1. A deep underground cavern contains 2.24 x 106 L of
methane gas (CH4) at a pressure of 1.50 x 103 kPa and a
temperature of 315 K. How many moles is this? How
many kilograms of CH4 does the caver contain?
2. When the temperature of a rigid hollow sphere
containg 685 L of helium gas is held at 621 K, the
pressure of the gas is 1.89 x 103 kPa. How many moles
of helium does the sphere contain? How many helium
atoms is this?
II. Ideal vs. Real Gases
Ideal Gases
Real Gases
Follow gas laws of temperature and
volume
Do have volume and attraction between
particles
Conform to kinetic theory of matter
Gases can turn into liquids and solids
No volume or attraction to particles
within the gas
Differences occur at low temps and high
pressures
Examples…No gases meet these rules all
the time
Look at pg. 429 “Ideal vs. Real Gases”
But…
Ex: Anything that is a gas or can become
a gas