BELL RINGER 2/3:What is heat? Explain.

OBJECTIVE: SWBAT describe the relationship between all 4 gas variables

AGENDA: -POGIL

7. In Model 1, what does a dot represent?

7. In Model 1, what does a dot represent?6. Name the two factors related to molecular movement that influence the pressure of a gas.13. Complete the following table for the three experiments in model 2.

SUMMARY:1. When volume and temperature are

constant, what is the relationship between number of molecules and pressure?

2. What causes that relationship?3. When volume and number of moles are

constant, what is the relationship between temperature and pressure?

4. What causes that relationship?

BELL RINGER 2/4:A gas in a glass flask with an initial

temperature of 150K is heated up until it reaches a temperature of 400K. Compared

to its initial pressure, will the gas’s new pressure be greater or lesser?

OBJECTIVE: SWBAT describe the relationship between all 4 gas variables

AGENDA: -POGIL-PRACTICE CALCULATIONS

7. In Model 1, what does a dot represent?6. Name the two factors related to molecular movement that influence the pressure of a gas.13. Complete the following table for the three experiments in model 2.

POGIL Discussion•1st Responder: Answer, with evidence

•2nd Responder: Agree or Disagree (provide counter-evidence, as necessary)

•3rd Responder: Summarize what each responder has said

POGIL Wrap Up•Why do you think they used a flexible container in Model 2?•What relationships (think Model 2) do you notice between:

•Amount of gas (number of moles) and volume?•Temperature and volume?•Pressure and volume?

•What is happening with the molecules in each of the above situations?

POGIL Wrap Up•Are each of the variables related individually, or are they all related?

•If they are all related, how might they be related (equation?)?

BELL RINGER 2/6:Can more energy be stored in air

or water? Hint: Think back to chemistry

and specific heat!

OBJECTIVE: SWBAT explain how the specific heat of an object and calculate specific heat and factors that contribute to it using C=Q/mT.

AGENDA: -Wrap up Ideal Gas Law Notes-Reading-Specific Heat Notes-Practice Calculations

GAS LAWS: Observations about the relationship between different factors that affect the behavior of gases lead to the ideal gas equation:

PV=nRTP=Pressure (in atm or kPa)V=Volume (in L)n=molesR= 0.0821 L*atm/K*mol OR 8.31 L*kPa/K*mol when pressure is in Pascals)T=Temperature in Kelvin

When you are given number of particles and NOT number of moles, you will use a different constant.

PV=nkTP=Pressure (in atm or kPa)V=Volume (in L)n=number of particlesk= 1.38 x 10-23 J/KT=Temperature in Kelvin

Reading Questions to Think About•Based on what you read, what is specific heat?•Explain the title of the article.•Does the amount of temperature change of the air correlate to the amount of solar energy trapped?•Will there be a limit to the energy storage in “Earth’s heat bucket”?

Reviewing Specific Heat•Specific heat capacity is the amount of energy required to raise the temperature of 1g of a substance by 10 C.

•More particles in substance = more heat energy!

•Higher temperature = more heat energy!

Reviewing Specific Heat

Equation:C=specific heat (J/g0C)Q=heat energy absorbed (+) or released (-)m=mass (g)T=change in temperature (final-initial)

€

C =Q

mΔT

Bellringer:If the specific heat of water is 4.18 J/g0C, and 120 g of water is heated from 130C to

380C, how much energy was added to raise the temperature?

OBJECTIVE: SWBAT explain how the specific heat of an object and calculate specific heat and factors that contribute to it using C=Q/mT.

AGENDA: -Bellringer-Review Homework-Quiz!!

Bellringer:Is energy added or released during a

phase change?

OBJECTIVE: SWBAT practice reading phase change diagrams.

AGENDA: -Bellringer-Open Response Quiz-Reading a Heating Curve

Heating Curve of Water

solid

liquid

gas

Melting Freezing

Boiling (Evaporation) Condensing

**Key Point•Latent Heat: is the energy absorbed or released during a constant temperature process.

•Example: Most examples of latent heat are phase Changes!

Discuss•Think about the equation for heat energy (Q=CmΔT). Why doesn’t this equation work during parts D and E on the graph?

Types of Latent Heat•Heat of Vaporization (ΔHv) = The amount of heat needed to change state from a liquid to a gas.

*Note: If a substance changes phase from a gas to a liquid ΔHv is negative.

Types of Latent Heat•Heat of Fusion (ΔHf)= The amount of heat needed to change state from a solid to liquid.

*Note: If a substance changes phase from a liquid to a gas ΔHf is negative.

Equations

Q = m × ΔHv

Q = m × ΔHf

Heating Curve of Water

solid

liquid

gas

Melting Freezing

Boiling (Evaporation) Condensing

Q = mcΔT

Q = mcΔT

Q =

mcΔ

T

Q = mΔHf Q =m-ΔHf

Q = mΔHV Q =m-ΔHV

Practice• For Water: Hf= 334 J/g Hv= 2,260 J/g• You want to melt 22 g of ice.

• Where is this phase change located on a heating curve?• What equation needs to be used to calculate the heat

needed to complete this phase change?• Calculate.

Practice• For Water: Hf= 334 J/g Hv= 2,260 J/g• You’re now boiling 286 grams of water to make tea.

• Where is this phase change located on the heating curve graph?

• What equation needs to be used to calculate the heat needed to complete this phase change?

• Calculate.

Practice• For Gold: Hf= 64.5 J/g Hv= 1,578 J/g

•How much heat is required to boil 6.2 g of gold?