Chemistry• PLEASE GET OUT YOUR PHET ONLINE

SIMULATOR HOMEWORK • HW SHEET• HAVE ONE PERSON IN YOUR GROUP TURN IN

“BOYLE’S LAB” ON GOOGLE CLASSROOM• Make sure you include everyone’s name!

• ASK YOUR PARTNER…

“WOULD YOU RATHER… TAKE AP CHEMISTRY NEXT YEAR, OR A DIFFERENT SCIENCE CLASS?”

Warm-up- Boyle’s Law should be turned in by now! What causes pressure? How did volume effect pressure?

What does this look like on a macroscopic level? What does this look like on the particle level? What does this look like on a mathematical level?

Learning Targets

Pressure vs. Volume – Boyle’s Law: Looking for Constants(k)Volume

(in mL)Pressure ( in kPa)

P/V P∙V = k

5.8 182.48 31.46 1058.38

7.8 140.31 17.99 1094.42

9.8 111.34 11.36 1091.32

11.8 90.45 7.67 1067.31

13.8 76.52 5.54 1055.98

15.8 57.71 3.65 911.81

17.8 58.34 3.28 1038.45

19.8 51.34 2.59 1016.53

Explaining the Graph

Explaining the Graph

Boyle’s Law

P/V or P ∙ V? If pressure increases, what

happens to volume? Mathematical Relationship?

Which gas law variables are being held constant?

How did you keep them constant in the lab?

P ∙ V If pressure increases, volume

decreases Indirect Relationship (variables

change in different direction) Same Temp + Same Moles

The air in the syringe had the same # of moles (they were just squished more) and it was at the same temp

Scientific Explanations Claim

A simple statement that clearly identifies the outcome (often the relationship between variables)

Evidence Data that is appropriate and sufficient to support the claim

Reasoning Justification that links the claim and evidence Shows why by using scientific concepts (like definitions, models, theories, or

laws) and background knowledge Often refers to resources such as lab books, articles, textbooks, and/or the

Internet

On a blank piece of paper…

Given a closed system in which the temperature stays the same, explain the relationship between pressure and volume of a gas. (Your claim should include a mathematical equation that demonstrates this relationship).

Practice with Boyle’s Law

Boyle’s Law—Think Questions

If in the first scenario you had your pressure/volume equaled that constant

P1V1=K And in the second scenario you had your pressure/volume equal to that

same constantP2V2= K

Couldn’t we simplify this?

P1V1=K=P2V2

P1V1=P2V2

Calculations: Solving for UnknownsSince PV = constant (k), then…

P1V1 = k = P2V2

P1V1 = P2V2

Sample: a balloon is inflated to a volume of 3.5 L at 1.25 atm. What is the volume of the balloon if it rises up to 0.50 atm?

P1= 1.25 atm V1= 3.5 L P2= 0.50 atm V2= ???(1.25 ∙ 3.5) = (0.50 ∙ V2)4.375 = 0.50 V2

V2 = 8.75 L sig figs 8.8 L

Consider this scenario…A balloon with a set amount of air has a volume of 6 L at sea level (1 atm). The balloon is brought underwater where the pressure is now 3 atm. Will the balloon’s volume decrease or increase? Explain why this makes sense. What will be the new volume of the balloon?

Ans: Consider this scenario…

A balloon with a set amount of air has a volume of 6 L at sea level (1 atm). The balloon is brought underwater where the pressure is now 3 atm. Will the balloon’s volume decrease or increase? Explain why this makes sense.

Pressure increased, therefore volume would decreaseWhat will be the new volume of the balloon?

P1V1 = P2V2 1 atm ∙ 6 L = 3 atm ∙ V2

V2 = 2 L

HW Review

Compare responses to the Gas Properties Simulator W.S I will be calling popsicle sticks for answers and examples!

Gas Laws!

Last Time! Today/Next Class

Next (& next) Time!!

Kelvin vs. Celsius To Avoid Negative Numbers: Absolute Temperature is measured in Kelvin. 0 K = -273°C K = 273 + °C °C = K -273

-273°C

0°C 25°C

50°C

0 K 273 K

298 K

323 K25

K

50 K

Gay-Lussac Lab

In the next 5 minutes…Please have (at least) two computer’s per lab stationHave one person log on to Google Classroom and download “Gay-Lussac’s Lab” and share with the rest of the group.Read the procedure (on google docs or paper)Fill up your beaker with tap water to ~350 mL

Gay Lussac’s Lab (P vs. T)1. Use the Pressure + Temperature sensors to determine the relationship between P and T2. Get the following data. (do half, and have a neighbor lab group do half and swap data)3. Use this data, come up with a formula for the relationship

Pressure(kPa)

Temp

(ₒC)

Temp

(K= C + 273)(P / T ) (P•T)

~0

~20

~50

~85

Are you already done? Are you already done? Double check and swap data on the Gay-

Lussac Lab Do you have:

Data table filled in, with units and sig figs?2 Graphs of temp vs. volume (in C, 2 Graphs of temp vs. volume (in C,

in K)?in K)? Answers to processing questions 1-4 in

complete sentences? Shared the Google Doc all your lab groups?

Homework: Homework: Finish GL LabFinish GL Lab#1-6 of BGC W.S#1-6 of BGC W.S

Pressure vs. Temperature – Gay Lussac’s Law

Pressure(kPa)

Temperature(K)

Constant k

(P / T )(P•T)

89.4 273.6 .33 243339

94.84 293.52 .32 27837

104.19 323.03 .32 33656

114.91 358.27 .32 41168

Absolute Zero on a Celsius Graph

Temperature & Absolute Zero Heat something = Add Energy to Atoms Atoms move ____________! Cool something = Removing Energy to atoms Atoms move

_____________! You can keep adding Energy, but there is only so much you can take

away!!! Limit to how “ColdCold” something can be.

ABSOLUTE ZERO -273°C or 0 K

FASTERFASTER

SLOWERSLOWER

Exit Task

Draw a simple line graph showing the relationship between pressure and volumeLabel the axes

Homework:Finish GL Law Lab on Google Docs

Exit TaskA 2.0 liter tank of oxygen gas is at a pressure of 3.5 atm. What volume of oxygen will be available if the oxygen is used at a pressure of 752 mm Hg?

Draw and Explain How I did this?

ANS on ETD 51AA. A 2.0 liter tank of oxygen gas is at a pressure of 3.5 atm. What

volume of oxygen will be available if the oxygen is used at a pressure of 752 mm Hg?