Gases revision

not all equations for the kinetic theory of gases are here - look in your book -  that section is hard to summarise and explain.

HideShow resource information
  • Created by: glow.
  • Created on: 02-03-13 11:07
Preview of Gases revision

First 105 words of the document:

In gas calculations, temperature MUST be in KELVINS.
Boyle's Law pV = k Constant T: water boils at fixed
p= k temp.
Pressure inversely proportional
to volume
Charles's Law V =k Constant p: Prince Charles!
Volume proportional to temp
Pressure Law P =k Only one left! Constant:
Pressure proportional to temp volume
Boyle's Law
Explanation: pressure increases by vol. decrease because gas molecules travel less distance
between impacts due to reduced vol. = more impacts per sec = increase pressure.
Charles's Law

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Pressure Law
Explanation: pressure increased by temp. increase because average speed of molecule increased
due to heat= impacts on container walls harder and more often = increase temp.
For questions:
You will only ever need to use one law.
So, if you need to use Boyle's law, and the volume of the gas changes:
p(1)V (1) = p(2)V (2)
You can use this method for all of the gas laws.
Molecules in a gas.
Move randomly with different speeds.…read more

Page 3

Preview of page 3

Here's a taster:

Avagadro used to find how many molecules are in a gas using 1g of H. We now used 12g 12-C
isotope because hydrogen gas was impure and the isotope of H, which made it impure, was hard to
1u: 1/12th mass of 12-C.
1u = 1.…read more

Page 4

Preview of page 4

Here's a taster:

Page 5

Preview of page 5

Here's a taster:

V = nkT
Mass MS of substance: Mn
Mass of ideal gas: MS: M( pV /RT )
Density of ideal gas: MS/V = pM/RT
Boltzmann constant : k= R/NA
Each impact on container wall causes a force on it. The force of many impacts is the cause of the
pressure of the gas on the container walls.
Molecules in gas have continuous spread of speeds.
Speed of individual molecule changes when it collides with
molecule, but distribution constant, proving temp is
constant.…read more

Page 6

Preview of page 6

Here's a taster:

Distribution becomes flatter and
Root mean square speed:
Assumptions about kinetic theory equation:
Molecules are point molecules
Molecules don't have electrostatic forces - don't attract/ repel
Move in continual random motion
Elastic collisions ­ no overall loss of KE
Each collision with container surface is of shorter duration than time between impacts.…read more

Page 7

Preview of page 7


No comments have yet been made

Similar Physics resources:

See all Physics resources »See all resources »