5.16

5.16.docx Download this file

5.14

5.14.docx Download this file

5.14

·         

5.14 describe the Kelvin scale of temperature and be able to convert between the Kelvin and Celsius scales

Converting Centigrade to Kelvin
T_K = T_oC + 273

Converting Kelvin to Centigrade
T_oC = T_K - 273

T_K = Temperature in Kelvin [K]

T_oC = Temperature in Degrees Centigrade [^oC]

5.14) Kelvin Scale & Absolute Zero.docx Download this file

PhET Gas Properties simulation

Click to Run

5.13

5.13 Starter

·         

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

5.13 Starter 2

·         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 –273^oC

	<<Charles' law interactive experiment.swf>>
			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

Conclusion

·         Volume is directly proportional to absolute (Kelvin) temperature

·         V Î± T

Charles' law interactive experiment.swf Download this file

5.11

5.11 Starter

·         

You're looking at smoke particles in air under a microscope

·         They appear to be jiggling about

·         Why?

 

·         (Don't worry if you can't work this out straight away - Albert Einstein was the bloke who eventually explained what's happening here!)

5.11

·         5.11 understand the significance of Brownian motion

Model 1

·         What does the red puck represent?

·         What do the metal balls represent?

			<<brownian_motion.swf>>

Model 3

·         What do the "smoke" particles look like?

·         Why are they moving?

·         What do the "air" particles look like?

5.11 explained

28 October 2011

11:10

Model 1

·         What does the red puck represent?

o    The large, visible smoke particle

·         What do the metal balls represent?

o    The small, not visible air particles

 

Model 2

·         What do the small red particles represent?

o    The small, not visible air particles

·         What does the large blue particle represent?

o    The large, visible smoke particle

·         What does the view on the left of the screen represent?

o    The view through the microscope lense

·         Why can't you see the red particles in this view?

o    They are too small to see

 

Model 3

·         What do the "smoke" particles look like?

o    They are the 5 large, sand coloured particles

·         Why are they moving?

o    Small, fast moving air particles are colliding with the smoke particles and making them move

·         What do the "air" particles look like?

o    They are the numerous, small, white particles

5.11 Questions

1. Draw the path of a smoke particle in air  (3 marks)

2. Explain what is meant by Brownian Motion of smoke particles in air and how it provides evidence for air particles  (4 marks)

3. What change would you expect to see in the movement of the smoke particles if the air was cooled down?  Why?  (2 marks)

brownian_motion.swf Download this file

5.12 + 5.15

This e-lesson consists of 3 objectives; 5.12, 5.15 and 5.11.  I’ll e-mail the other objective separately.

Instructions for Objective 5.12 and 5.15

1.    

5.12+5.15 Starter.  Watch the video and think about the question.  No need to type anything.

2.    5.12+5.15 Questions.  Open the animation.  Forward this e-mail to your blog and complete the questions.

3.    5.12+5.15 Plenary.  Open the attached ppt.  View as slide show.  Think about what the blanks in the table are.  Check your answers with slide 2.  No need to type anything.

4.    Answers to step 2 will be sent separately.  Don’t look at them until you’ve done the work!

Best wishes,

Mr B

5.12+5.15 Starter

	<<Video - simulation of gas pressure in Phun.flv>>

Questions

·         Why does the needle on the meter move when gas particles are introduced into the box?

·         What does the meter measure?

Answers

·         The gas particles collide with all of the walls of the container.  The wall on the right moves outwards and moves the needle.

·         Pressure.  The gas particles colliding with the walls makes a force on the walls.  The walls have a surface area so the quantity measured is pressure, p=F/A.

5.12+5.15 Questions

·         

5.12 recall that molecules in a gas have a random motion and that they exert a force and hence a pressure on the walls of the container

·         5.15 understand that an increase in temperature results in an increase in the speed of gas molecules

Try the animation 

http://www.lon-capa.org/~mmp/kap10/cd283.htm

1.    How do the particles create a pressure?

Because gas molecules are moving around at random motion, they eventually collide into the wall of the container, exerting force on its surface.

2.    

If you increase the temperature, how does the movement of the particles change?

The speed of the movement of gas molecules increases due to the increase in average kinetic energy.

3.    

If you increase the temperature, how does the number of collisions per second change?

The collisions per second increases.

4.    

If you increase the temperature, what does this do to the pressure?

The pressure increases due to the increase in kinetic energy, which increase the collision of gas molecules to the wall. As a result, more force is being exerted onto the wall of the container and therefore pressure increases. 

5.12+5.15 Plenary

<<Ideal gases - summary of terms.pptx>>

Ideal gases - summary of terms.pptx Download this file