Ch 9 Ppt
Card Set Information
Author:
DesLee26
ID:
192870
Filename:
Ch 9 Ppt
Updated:
2013-01-27 23:57:55
Tags:
CHM 112
Folders:
Description:
Gases: Their Properties and Behavior
Show Answers:
Gas mixtures are __ and __.
homogeneous
compressible
Gases above us __ on us, causing __ affected by the __.
push down
pressure
gravitational pull
What is the typical tool for measuring pressure?
barometer
What is the amount of mercury that goes in a barometer?
760 mm
In a barometer, as the pressure incresaes, what happens to mercury?
As the pressure decreases, what happens to mercury?
pressure increses, mercury goes up; greater height
pressure decreases, mercury goes down; smaller height
Ideal Gas
a gas whose behavior follows the gas laws exactly; independent; a gas that doesn't interact with anything
THe physical properties of a gas can be defined by four variables:
pressure
temp in K
volume
number of moles
What is the formula for the Combined Gas Law?
(P1V1/T1)=(p2V2/T2)
Another name for Boyle's Law?
Relationship between volume and pressure?
Pressure-Volume Law
inverse relationship
Another name for Charles' Law?
Relationship between volume and temperature?
Temperature- Volume Law
directly proportional
Significance of absolute zero?
no motion
Formula for:
Boyle's Law
P1V1=P2V2
Formula for:
Charles' Law
V1/T1=V2/T2
Formula for:
Avogadro's Law
V1/n1=V2/n2
Ideal gases obey an equation incorporating the laws of __, __, and __.
The formula is:
Charles, Boyle, and Avogadro
PV=nRT
Formula for:
Density and Molar Mass Calculations
d=mass/ volume= (n x M)/ V = (P x M)/ (R x T)
You can calculate the __ or __ of a gas. The density of a gas is usually very __ under atmospheric conditions.
density
molar mass (M)
low
In __, for a constant temperature and pressure, volume is __ to moles.
gas stoichiometry
proportional
Mole Fraction
X
_{i}
= (n
_{i}
)/(n
_{total}
) or
X
_{i}
= P
_{i}
/P
_{total}
Kinetic Molecular Theory:
What does it present?
physical properties of gases in terms of hte motion of individual molecules
Postulates of Kinetic-Molecular Theory:
1
A gas consists of tiny particles, either atoms or molecules, moving about at random
Postulates of Kinetic-Molecular Theory
2
The volume of hte particles themselves is negligible compared with the total volume of the gas; most of the volume of a gas is empty space
Postulates of Kinetic-Molecular Theory
3
The gas particles act independently of one another; there are no attractive or repulsive forces between them
Postulates of Kinetic-Molecular Theory
4
Collisions of the gas particles, either with other particles or with the walls of a container, are elastic (constant temp)
Postulates of Kinetic-Molecular Theory
5
The average kinetic energy of the gas particles is proportional to the Kelvin temperature of the sample
What is Root-Mean-Square
measure of the average molecular speed
Diffusion
mixing of different gases by random molecular motion and collision
Effusion
when gas molecules escape without collision, through a tiny hole into a vacuum
Graham's Law
rate of effusion is proportional to its rms speed
Deviation results from assumptions about ideal gases. What are the two
molecules in gaseous state do exert any force, either attractive or repulsive on one another
Volume of the molecules is negligibly small compared with that of the container
The volume of a real gas is __ than predicted by the ideal gas law.
larger
At lower pressure, the volume of the gas particles is __ compared to the total volume.
negligible
At higher pressure, the volume of the gas particiles is __ to the total volume.
more significant compared
The volume ofa real gas at high pressure is __ than the ideal value.
larger
Attractive forces between particles become more important at __.
higher pressures