Chemistry - Gas Laws N a m e

Period Date

Gas Laws Computer Activity #1

Pressure and TemperatureG o t o h ies . Click on "Run Now.,,ln this activity, you will be looking at the relationship between pressure and temperature of a gas.First, you need to add a gas to your container. Change the "Gas in Chamber,, to read 100 molecules ofHeavy (blue) species,

Describe the motion of the particles:

Grab the handle of the pump and add another pump-full. Besides the obvious change in the amount ofgas, what else changes in your container?

Click the "Reset,, button in the lower right.ln this activity, we want to examine the rerationship between pRESS )JRE andmust set your container to constant volume. Click on the Volume bufion in theupper right corner. This should lock your volume at a constant value.As soon as you serect constant vorume, what happens to the box?

change the gas to 20o molecules of the HEAW species by manuaily setting this in the right box.You are going to adjust the temperatureof the container by adding or removing heat using the Heat controtunder the container. The temperature of the internal envii6nment is found aboie the container.In what units is temperature reported?

TEMPERATURE onty. you"Constant Parameters', on the

Using the internet, determine the relationship between Kelvin and celsius.

Temperature is a rerative measure of energy. what temperature is your box at?Increase the temperature by using the "Heat control,, under your container.motion of the particles in your container?Decrease the temperature. what happens to the motion of the particres?Return the temperature to 300 K.The pressure gauge is found on right side of the container.What units is the pressure measured in?Again, increase the temperature to 600 K.what happens to the number of collisions between the molecules and the container wall?

How does this affect fhe

ln the end, how does this change affect the pressure of the container? what is the new pressure?

Fill in Data Table #1 by selecting various temperatures and recording the corresponding pressure on thepressure gauge. choose a wide range of temperatures. But don't go too hot!

lnclude units. calculate the values as indicated in the other columns.

DATA TABLE #1Trials Temperature (T) Pressure (P) Calculate k1 = (Pxl)

Calculate k, =FTrial 1 300 K

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3

4

5

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Which variable did you manipulate (independent)?

Which variable is the dependent variable?

Graph Pressure vs. Temperature in the following graph. Use proper scaling. Label the graph appropriately.Graph the line of best fit.

Looking at your data and graph, describe the relationship between temperature and pressure.

As the temperature gets colder and approaches 0 K, what happens to the motion of the particles?

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Fil l in the fol lowing chart by selecting various Volumes. Measure the volume of the container using the ruler.

Calculate the values as indicated in the other columns.

Trials Volume (V) Pressure (P) Caf culate k1= pxlf PvCalculate k2 =

Trial 1

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5

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Which variable did you control ( independent)?

Which variable is the dependeht variable?

Graph Pressure vs. Volume in the following graph. Use proper scaling. Labelthe graph appropriately. Draw acurved line best connecting all of the points.

Looking at your data and graph, describe the relationship between volume and pressure.

As the volume gets larger, what happens to the pressure of the gas?

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Which value remains consistent in the data table? k1 _ or kz

This k-value is constant; the ratio between volume and temperature of any point on the graph wil l be thesame. Pick any two points from the graph or table:

Point #L point #2

Vr = Vz=

P r = P t =

Show the k-value calculation:

Write an equation for Boyles's Law:

We can use this formula to predict the pressure (P2) or volume (V2) of any gas. Use this formula to completethe following calculations. Show your work.

L . l f a g a s h a s a v o l u m e o f L . 2 5 L a n d a p r e s s u r e o f L . T l a t m , w h a t w i l l t h e p r e s s u r e b e i f t h e v o l u m e i schanged to 3.15 L?

2. l f a gas has a volum e of 3.67 L and a pressure of 790 mm Hg, what wil l the pressure be if the volume iscompressedto 2.LZ L? What is the pressure in atmospheres (atm)? Convert pressure units.

3. A container has a volume of 5.85 L and a pressure of 4.25 atm. What wil l the volume be if thecontainer's pressure is changed to 2.75 atm?

4. A container has a volume of 2.79 L and a pressure of 5.97 atm. l f the pressure changes to 1460 mm Hg,what is the container's new volume? Convert pressure units.

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As the temperature gets approaches 0 K, what happens to the pressure of the container?

Increase the temperature to 2000 K, what happens to your container?

Which value remains consistent in the data table? kr or kzNote: the other k-value is worthless and proves nothing.

Looking at the top of Data Tabre #1, what does this ,,k,,value equar?

Let's call the first set of data points P1 and 11 and the second set of data points p2 and 12 and so on. since alltrials have roughly the same chosen k-value, set the r<-uuru"r to equal each other. write an appropriateequation using the variables pr, Tr, pz, dtldTz.

This is Gay'Lussac's Law between Pressure and remperature of a Gas. Learn it. Know it. use it.we can use this formula to predict the pressule (Pr) or temperature ffr) of any gas. Use this formula tocomplete the following calculations. when doing tn'ese catiutations,'it is n"."lr"ry for the pressure to havethe same units. ldentify all variables and then .in.titut"

"no solve.

1' lf a gas has a pressure of 1.69 atm at a temperature of 300 K, what will the pressure change to if thecontainer is cooled to 100 K?

2' lf a gas has a pressure o'f 715 mm Hg 3ltn." temperature of 500 K, what will the pressure change to ifthe container is heated to 900 K? wrrat is ilris frJssuie in atmz

3' on the side of aerosol cans, there is warning against heating the container. lf the gas inside thecontainer is at a pressure of 5.9 atm at roonite-mperature .eb" c),wnat wiit the pressure of the can be ifthe can is heated to 100' c? Remember to coniert io-Ketvin.

4. lf a container of gas has a temperature of 2g0 K andyou have to heat the container to achieu" u pr"..uru

a pressure of 1.85 atm, to what temperature wouldof 4.75 atm?

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Chemistry - Gas Laws NamePer iod Date

Gas Laws Computer Activity #2

Volume and Temperature

Go to http://ph et.colorado.edu/en/simu lation/eas-properties . Click on "Ru n Now."

ln this activity, you will be looking at the relationship between VOLIJME and TEMPERATIJRE of a gas.

First, you need to add a gas to your container. Change the "Gas in Chamber'n to read 100 molecules ofHeavy (blue) species. Let the box equilibrate.

What is the pressure of your container?

ln this activity you are examining the relationship betwe en VOLTJME and TEMPERATIJRE only. you mustset your container lo constant pressure. Click on the Pressure button in the "Constant Parameters" in theupper right corner. This should lock your pressure at a constant value (it might fluctuate a very small amount).

As soon as you set the pressure to constant, what happens to the little man next to the box?

This little robot is responsible for changing the volume of the container. His position will fluctuate. When youare trying to measure the volume of the container, you must estimate the best averaqe position aidrecord this value,

This simulation does not have a tool to measure the volume of the container, so we need to devise one.

Glick on the ooMeasurement Tools" button on the right side. Glick on the Ruler.

This will cause a ruler to appear. The rulers units are in nanometers (nm) but we are going to use the ruler togive us an estimated measurement of volume. Click on and drag the ruler anywhere you want. You willuse the ruler to measure the width of the box. We will then change the units of measurement to liters. Forexample: initially the box should have a width of 6.6 nm which will be recorded in your data table as 6.6 L(liters), When you are asked to change/measure the volume of the box, use the ruler to do so.

What are the graduations on the ruler? (How much is each notch worth?)

You are going to adjust the temperature of the container by adding or removing heat using the Heat Controlunder the container. The temperature is found above the container.

What units is temperature measured in the container?

Write an equation relating degrees Celsius and Kelvin:

|ncreasethetemperature,whathappenstothemotionofthepart ic |es?

We set pressure to be a constant value. What causes pressure in the container?

lf the particles are moving faster but we don't want them to hit the walls anymore than previously, what is goingto have to change??? Think about it.

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Fill in Data Table #2 by selecting various temperatures and measuring the corresponding volume of thecontainer using the ruler. use temps between lso K and 4so Kl

calculate the values as indicated in the other columns.

Trials Temperature (T) Volume (V) Calculate k1= (VxT)Calculate k, =F

Trial 1 300 K

2

3

4

5

6

Which variable did you manipulate (independent)?

Which variable is the dependent variabte?

Graph Volume vs. Temperature in the following graph.Graph the line of best fit.

Use proper scaling. Label the graph appropriately.

Looking at your data and graph, describe the relationship between temperature and volume.

As the temperature gets colder and approaches 0 Kelvin, what happens to the volume of the gas?

Which value remains consistent in the data table? kr or kz

NotCi the othei k-value is worthleis and proves nothing.

Looking at the top of Data Table #2, what does this "k" value equal?

Let's call the first set of data points V1 and T1 and the second set of data points V2 and T2 and so on. Since alltrials have roughly the same chosen k-value, set the k-values to equal each other. Write an appropriateequation using the variables V1, T1, V2, dhd T2.

This is Charles' Law between Volume and Temperature of a Gas. Learn it. Know it. Use it.

We can use this formula to predict the volume (Vr) or temperature (Tj of any gas. Use this formula tocomplete the following calculations. When doing these calculations, it is necessary for the pressure to havethe same units. ldentify allvariables and then substitute and solve.

1 . lf a gas has a volume of 1.25 L at a temperature of 300 K, what will the volume change to if thecontainer is cooled to 200 K?

2. lf a gas has a volume of 3.67 L at the temperature of 500 K, what will the volume change to if thecontainer is heated to 900 K?

3. A balloon bought in a store where the temperature is 22 C has a volume of about 3.12 L. The persontakes the balloon outside on a hot day of a temperature is 37" C. What is the new volume of theballoon? Becareful of the Temp Units!!!

4. lf you did buy a 2.75 L balloon that had a temperature of 23' C, what temperature would you have toheat the balloon to in order to increase the volume to 5.00 L?

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