12.2 Ideal Gas Basics and Boyle's Law Flashcards
What 4 variables do we have to consider when looking at behaviour of gases?
mass
pressure
volume
temperature
How can we investigate how these quantities are related?
By keeping 2 constant while we see how others will vary?
What is an ideal gas?
One which has internal energy depending only on the kinetic energy of the molecules - there is no potential energy?
Is an ideal gas theoretical?
Yes
What does an ideal gas obey?
The 3 gas laws - Boyles,Charles and Pressure
What equation does an ideal gas obey? Under what conditions?
pV = NkT
or
pV = nRT
under all conditions of temperature and pressure
What are the 3 laws we have to be aware of?
Boyle’s
Charles’
Pressure
What relationship does Boyle’s Law describe?
Relationship between pressure and volume.
What is kept the same in Boyle’s Law?
Mass and Temperature
What does Boyle’s Law state?
That the pressure for a fixed mass of a gas is inversely proportional to volume provided that temperature is kept constant.
Boyle’s Law numerically?
p = 1(k)/v
What is the equation for Boyle’s Law when the gas undergoes changes?
p1v1 = p2v2
Why does this equation exist?
As pv = constant, as p and v are inversely proportional.
What does a a p against V graph look like?
http://www.schoolphysics.co.uk/age16-19/Thermal%20physics/Gas%20laws/text/Gas_laws/index.html
What does a p against 1/v look like?
A straight line going through the origin
What does a graph of pV against p or v look like?
Horizontal line from pV
Why is it just a horizontal line?
As pV = constant and constant stays the same throughout
If temperature was higher what would happen to a p against V graph?
It would move further away from the origin.
If temperature was higher what would happen to a p against 1/V graph?
Would get steeper
If temperature was higher what would happen to a p against 1/V graph?
The line would be higher. pV would be greater
Why does pressure increase as volume decreses?
As molecules which are closer together are more likely to collide
What do we assume when working with Boyle’s Law?
Density of fluid is uniform
mass and temperature are constant
What is the meaning of isothermal
An isothermal process is a change of a system, in which the temperature remains constant: ΔT =0.
Is boyle’s law isothermal?
Yes
What is the setup for a practical investigating boyle’s law?
We have a bourdon gauge,oil reservoir, pump, a scale wit oil and air.
Describe how this practical works?
The oil traps the air in the scale with a tube of fixed dimenstion.A tyre pump is used to increase the pressure as oil is pumped into the tube compressing the air, reducing the volume occupied by the air. Measuring the volume at 1atm , then graduallyu increasing pressure while keeping temperature and mass the same.Record
