5.18 Gay-lussac's law

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5.18 Gay-lussac's law

28 October 2011

11:11
· 5.18 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume:

p1 / T1 = p2 / T2

p1 = Pressure at the beginning [kPa, bar or atm ]

T1 = Absolute temperature at the beginning [K]

p2 = Pressure at the end [kPa, bar or atm]

T2 = Absolute temperature at the end [K]

(Note: the units of temperature must be Kelvin, not oC! The units of pressure can be any, as long as the same at the beginning and the end)

5.18 Experiment

07 November 2011

14:32
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· Change the temperature of a fixed mass of gas at a constant volume
· Measure the pressure
· Use the EXCEL spreadsheet to analyse your results

5.18 Ideal graph and conclusion

09 November 2011

15:15
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5.18 Question

07 November 2011

15:08

Collins, p.116

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a. If we cool the gas in a rigid, sealed tin can, what happens to the pressure inside the can? (1 mark)
b. Explain your answer to part a. by using the Kinetic Theory (4 marks)

Ideal Gas - Gay Lussac's law real results.xlsx Download this file

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5.17

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5.17 starter

02 November 2011

20:01

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Why do the eggs get sucked into the bottles?!

Explanation
· The burning paper in the bottle heats the air in the bottle
· When the egg gets placed on top, the oxygen supply in the bottle is rapidly depleted and the paper goes out
· The bottle is sealed by the egg and now has a constant volume of gas inside
· The hot gas in the bottle now starts to cool which reduces the pressure inside the bottle
· The pressure outside the bottle remains unchanged and so there is now an unbalanced force on the egg which accelerates the egg into the bottle

5.17

28 October 2011

11:11
· 5.17 describe the qualitative relationship between pressure and Kelvin temperature for a gas in a sealed container

Instructions
· Launch the application on this website: http://phet.colorado.edu/en/simulation/gas-properties

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· Put 5 pumps of gas in
· Set volume as the Constant Parameter
· Heat to 1000K
· Watch what happens to the Pressure

Conclusion
· If you increase the temperature, you increase the pressure

5.17 Demo

02 November 2011

19:56

Cloud formation
· Place a little water in the bottom of a 1½ litre plastic bottle
· Squeeze a few times
· Introduce a small amount of smoke
· Squeeze and release several times
· When you squeeze, the cloud disappears; when you release, the cloud reforms

Explanation
· When the pressure increases the temperature increases and vica versa
· The "cloud" is water droplets - liquid water
· When you squeeze the bottle the temperature increases and the droplets turn into water vapour
· The smoke particles are nucleating sites on which the water can condense

5.13

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5.13 Starter

02 November 2011

18:17
· How can you fit a giraffe, 2 dogs and a swan into a standard laboratory beaker?!

5.13 Starter 2

02 November 2011

18:17

· Use particle theory to explain why the gas in the balloon contracts

Explanation
· The temperature of the gas inside the balloon decreases so the average speed of the particles decreases
· Consequently the gas particles collide with the walls of the balloon with less force and less collisions per second
· Because the walls of the container are flexible, the volume decreases

5.13 Charles' law

28 October 2011

11:10
· 5.13 understand that there is an absolute zero of temperature which is –273oC

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Open the Charles' law interactive experiment
· Adjust the temperature
· What’s the relationship between temperature and volume?
· Plot a graph of V against T
· Take a screen shot of the graph

5.13 results and conclusion

28 October 2011

11:10
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Conclusion
· Volume is directly proportional to absolute (Kelvin) temperature
· V α T

Charles' law interactive experiment.swf Download this file

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5.14

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5.14

28 October 2011

11:10
· 5.14 describe the Kelvin scale of temperature and be able to convert between the Kelvin and Celsius scales

Converting Centigrade to Kelvin
TK = ToC + 273

Converting Kelvin to Centigrade
ToC = TK - 273

TK = Temperature in Kelvin [K]

ToC = Temperature in Degrees Centigrade [oC]

5.14 Questions

02 November 2011

18:29
· Collins p.118

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5.7 and 5.8

Instructions for Objective 5.7 and 5.8

1.    5.7 and 5.8 Starter.  Find out the names of the processes.  Research on the internet if necessary.  No need to blog this.

2.    5.7 and 5.8.  Forward this e-mail to your blog and type the answers into the e-mail.

3.    5.7 and 5.8 Experiment.  I’m afraid you can’t do the expt until we get back but watch the video clip to see how it’s set up and have a look at the graph of the results.

4.    5.7 to 5.10 Plenary 1.  Play the attached “States of Matter”

5.    5.7 to 5.10 Plenary 2.  Play the attached “Fill the trucks”

6.    PhET States of matter simulation - embedding into your Posterous blog.  Embed in your blog and then have a play

 

5.7 and 5.8 Starter

28 October 2011

11:00

·         What are the 6 processes shown by the arrows?

 

 

 

5.7 and 5.8

28 October 2011

10:20

·         5.7 understand that a substance can change state from solid to liquid by the process of melting

·         5.8 understand that a substance can change state from liquid to gas by the process of evaporation or boiling

·         Questions from Collins p.112

·         Answer in Bullet Points!

Q1. A) solids keep their shape because the particles are so tightly packed together that they only vibrate in their fixed position. Liquids don’t because they are less packed together because there is more kinetic energy and they are free to move in the shape of their container. Gases have so much kinetic energy that they have no fixed shape and are free to move anywhere.

b) Gases have a lot of kinetic energy, due to heat. This causes the particles to be less dense than liquids or solids and causes them to float and fill their entire container

Q3. Boiling happens when there is high temperatures in a liquid which cause the liquid to have more kinetic energy, evaporation occurs when temperatures go any higher than boiling point, or on the top of the liquid during boiling

·   Use following pages from Collins as a resource to help you

 

 

5.7 and 5.8 Experiment - Cooling Curve of Stearic Acid using datalogger

15 October 2010

14:34

 

 

5.7 to 5.10 Plenary 1

28 October 2011

12:19

			·         Play the Stage 1 game to test your knowledge of solids, liquids and gases ·         Play the Stage 2 game to test your knowledge about changes of phase!

 

 

5.7 to 5.10 Plenary 2

28 October 2011

12:19

			Play the Level 1 game to test your knowledge of the properties of solids, liquids and gases

Extension: Play the Level 2 game to extend your knowledge about changes of phase!

 

 

 

PhET States of matter simulation - embedding into your Posterous blog

28 October 2011

11:14

·        Create a post

·         Turn on HTML editor

·         Copy in this text and Publish

<div style="position: relative; width: 300px; height: 225px;">

Click to Run

</div>

·         Success!  Now have a play with the simulation...

states of matter drag and drop plenary.swf Download this file

Fill the trucks - Properties of s,l,g.swf Download this file

5.9 and 5.10

 

 

 

·         5.9 recall that particles in a liquid have a random motion within a close-packed irregular structure

·         5.10 recall that particles in a solid vibrate about fixed positions within a close-packed regular structure

State	Particle Picture	Arrangement of Particles	Motion of Particles	Other Properties
Solid		·         closely packed ·         regular pattern	·         vibrate about a fixed position	·         fixed shape ·         not easily compressed since particles are closely packed ·         Strong bonds
Liquid		·         closely packed ·         no pattern	·         free to flow over each other	·         takes shape of its container ·         can be packed ·         not easily compressed since particles are closely packed ·         Weak bonds
Gas		·         widely spaced ·         no pattern	·         very fast moving ·         random directions	·         fills its container ·         can be packed ·         easily compressed since its particles are far apart ·         Very weak bonds

s,l,g animation.swf Download this file