the ideal gas equation n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
The Ideal Gas Equation PowerPoint Presentation
Download Presentation
The Ideal Gas Equation

Loading in 2 Seconds...

play fullscreen
1 / 14

The Ideal Gas Equation - PowerPoint PPT Presentation


  • 171 Views
  • Uploaded on

The Ideal Gas Equation. pV = nRT. The Ideal Gas Equation. Changing the temperature and pressure of a gas will change its volume. If the volumes of gases are not at stp we need to use the ideal gas equation What is an “ideal gas”?. An Ideal Gas. Identical particles in rapid random motion

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'The Ideal Gas Equation' - dylan-barry


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
the ideal gas equation1
The Ideal Gas Equation
  • Changing the temperature and pressure of a gas will change its volume.
  • If the volumes of gases are not at stp we need to use the ideal gas equation
  • What is an “ideal gas”?
an ideal gas
An Ideal Gas
  • Identical particles in rapid random motion
  • Particles = hard spheres of negligible size
  • Particles don’t react when they collide
  • Collisions between particles are elastic
    • Kinetic energy before = kinetic energy after
  • No intermolecular forces
the effect of pressure
The Effect of Pressure
  • At constant temperature

Increasing pressure

Gas compressed into smaller volume

Volume decreases as pressure increases

V is indirectly proportional to p

V  1/p

the effect of temperature
The Effect of Temperature
  • At constant pressure

Gas increases in volume

Increasing temperature

Volume increases as temperature increases

V is directly proportional to T

V  T

the effect of number of moles
The Effect of Number of moles
  • At constant temperature & pressure

“n” moles

2n moles

Volume increases as number of moles increases

V is directly proportional to n

V  n

slide7

V T

V  1/p

V  n

  • If we combine these three equations

V nT p

R = gas constant

V = RnT p

pV = nRT

the ideal gas equation2
The Ideal Gas Equation
  • p = pressure (Pa)
  • V = volume (m3)
  • n = number of moles
  • R = the gas constant = 8.31JK-1mol-1
  • T = temperature (K)

pV = nRT

converting units
Converting Units
  • Temperature
  • 0oC = 273K
  • a OC → a + 273K
  • Pressure
  • 1kPa = 1000Pa
  • a kPa = a x 1000Pa
converting units1
Converting Units
  • Volume
  • 1m = 10 dm = 100 cm
  • 1m3 = 103 dm3 = 1003 cm3
  • 1m3 = 1000 dm3 = 1 000 000 cm3
  • 1dm3 = 1 1000

m3

= 1 x 10-3 m3

m3

  • 1cm3 =1 1000 000

= 1 x 10-6 m3

what volume is occupied by 0 25 mol of a gas at 200kpa and 27 o c
What volume is occupied by 0.25 mol of a gas at 200kPa and 27oC?

1. Convert units

200kPa =

200 x 1000 Pa

= 2 x 105 Pa

27oC =

27 + 273

= 300K

2. Rearrange pV = nRT Equation

V = nRT p

V = 0.25 x 8.31 x 300 2 x 105

V = 3.12 x 10-3 m3

at 571k a 0 6g sample of he occupies a volume of 7 0 dm 3 calculate pressure
At 571K a 0.6g sample of He occupies a volume of 7.0 dm3, Calculate pressure.

1. Convert mass into moles n=m/Mr

n = 0.6 4

= 0.15

2. Convert units

= 7.0 x 10-3 m3

7.0 dm3 =

7

1000

3. Rearrange pV=nRT Equation

p = 0.15 x 8.31 x 571 7 x 10-3

p = nRT V

p = 1.02 x 105 Pa

slide13

0.71g of a gas when contained in a vessel of 0.821dm3 exerted a pressure of 50.65kPa at 227oC. Use these data to calculate Mr of the gas

1. Convert units

0.821dm3 =

= 8.21 x 10-4 m3

0.821/1000 m3

227oC =

227 + 273

= 500K

5.065 x 104 Pa

50.65kPa =

50.65 x 1000 Pa =

2. Rearrange pV = nRT Equation

n = pV RT

n = 5.065 x 104 x 8.21 x 10-4 8.31 x 500

n = 0.01 mol

slide14

0.71g of a gas when contained in a vessel of 0.821dm3 exerted a pressure of 50.65kPa at 227oC. Use these data to calculate Mr of the gas

3. Calculate Mr using n = m/Mr

= 0.71 0.01

Mr = m n

= 70.94

4. Check final answer

Gases are small molecules

– they rarely have Mr values over 100