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I. Grade Level/Unit Number: 9-12 /Unit 10

II. Unit Title: Kinetic Molecular Theory

III. Unit Length: 5 days

IV. Major Unit Goal / Learning Outcomes:

Students should be able to: Know characteristics of ideal gases Apply general gas solubility characteristics

Students should be able to use the following formulas and concepts of kinetic molecular theory:

1 mole of any gas at STP=22.4 L Ideal gas equation (PV=nRT), Combined gas law (P1V1/T1 = P2V2/T2) and applications holding one

variable constant (PV=k), P1V1 = P2V2

Boyle’s Law (V/T=k), V1/T1= V2/T2 Charles’ Law (P/T=k), P1/T1 = P2/T2 Gay-Lussac’s Law

o (Note: Students should be able to derive and use these gas laws—Boyle’s, Charles, Gay-Lussac’s—but are not necessarily expected to memorize their names.)

Avogadro’s Law (n/V=k), n1/V1 = n1/V2 Dalton’s Law (Pt=P1+P2+P3 …) Vapor pressure of water as a function of temperature (conceptually)

V. Content Objective (with RBT tags):

VI. English Language Development Objectives (ELD) Included:NC English Language Proficiency (ELP) Standard 4 (2008) for Limited English Proficiency Students (LEP)- English Language learners communicate information, ideas, and concepts necessary for academic success in the content area of science.

Chemistry- Unit 10 DRAFT 1

ObjectiveNumber

Content Objective RBT Tag

2.05 Analyze the basic assumptions of kinetic molecular theory and its applications: Ideal Gas Equation. Combined Gas Law. Dalton’s Law of Partial Pressures.

C3

Suggestions for modified instruction and scaffolding for LEP students and/or students who need additional support are embedded in the unit plan and/or are added at the end of the corresponding section of the lessons. The amount of scaffolding needed will depend on the level of English proficiency of each LEP student. Therefore, novice level students will need more support with the language needed to understand and demonstrate the acquisition of concepts than intermediate or advanced students.

VII. Materials/Equipment Needed:Activity MaterialsDemo #1 2 600mL beakers

Methylene BlueHot waterWide Rubber bands (1 per student)

Demo #2 Ping pong paddle and ballBoyle’s Law: Pressure-Volume Relationship in a Gas

LabPro or CBL 2 interfaceTI Graphing CalculatorVernier Gas Pressure Sensor or Pressure SensorDataMate Program20-mL gas syringe

Dalton’s Law Demonstration Erlenmeyer flaskone hole stopperglass tubing (bent)Rubbing tubinglarge test tube large container of water3M HCl Zinc (mossy)index card

VIII. Detailed Content Description:Please see the detailed content description for each objective in the chemistry support document. The link to this downloadable document is in the Chemistry Standard Course of Study at:http://www.ncpublicschools.org/curriculum/science/scos/2004/24chemistry


http://www.ncpublicschools.org/curriculum/science/scos/2004/24chemistry

IX. Unit Notes:

This unit is focused on the concept of the kinetic molecular theory and its applications. More specifically, students should be able to relate the pressure, volume and temperature of a gas using Boyle’s law, Charles’ law and the combined gas law. They will use the Ideal gas law to relate pressure, volume, temperature and moles of a gas. Students will be able to use Dalton’s law of partial pressures to relate the total pressure of a mixture of gases to the partial pressure of the component gases.

In each unit, Goal 1 objectives which relate to the process of scientific investigation are included. In each of the units, students will be practicing the processes of science: observing, hypothesizing, collecting data, analyzing, and concluding. The Goal 1 Objectives are as follows:

COMPETENCY GOAL 1: The learner will develop abilities necessary to do and understand scientific inquiry.1.01 Design, conduct and

analyze investigations to answer questions related to chemistry.

Identify questions and suggest hypotheses.

Identify variables. Use a control when

appropriate. Select and use

appropriate measurement tools.

Collect and organize data in tables, charts and graphs.

Analyze and interpret data.

Explain observations. Make inferences and

predictions. Explain the

relationship between evidence and explanation.

Identify how scientists share findings.

This goal and these objectives are an integral part of each of the other goals. In order to measure and investigate scientific phenomena, students must be given the opportunity to design and conduct their own investigations in a safe laboratory. The students should use questions and models to formulate the relationship identified in their investigations and then report and share those finding with othersStudents will be able to: Identify questions and suggest hypotheses. Identify variables. Use a control when appropriate. Select and use appropriate measurement

tools. Collect and organize data in tables, charts and

graphs. Analyze and interpret data. Explain observations. Make inferences and predictions. Use questions and models to determine the

relationships between variables in investigations.

Identify how scientists share findings.


X. Global Content: 21st Century SkillsOne of the goals of the unit plans is to provide strategies that will enable educators to develop the 21st Century skills for their students. As much as students need to master the NCSOS goals and objectives, they need to master the skills that develop problem solving strategies, as well as the creativity and innovative thinking skills that have become critical in today’s increasingly interconnected workforce and society. The Partnership for 21st Century Skills website is provided below for more information about the skills and resources related to the 21st Century classroom.

http://www.21stcenturyskills.org/index.php?option=com_content&task=view&id=27&Itemid=120

NC SCS Chemistry 21st Century Skills Activity

Communication Skills1.01 & 2.05 Conveying thought or opinions effectively KMT Practice

Questions Introducing Direct

and Indirect Relationships

Boyle’s, Charles’ & Combined Gas Law Problems

Boyles’ Law Lab Exploring Ideal Gas

Law Ideal Gas law

Problems Dalton’s Law

Practice Problems

1.01 & 2.05 When presenting information, distinguishing between relevant and irrelevant information

1.01 & 2.05 Explaining a concept to others KMT Practice Questions

Introducing Direct and Indirect Relationships


Boyles’ Law Lab




Exploring Ideal Gas Law

Ideal Gas law Problems

Dalton’s Law Practice Problems

Interviewing others or being interviewedComputer Knowledge

1.01 & 2.05 Using word-processing and database programs

1.01 & 2.05 Developing visual aides for presentations1.01 & 2.05 Using a computer for communication

Learning new software programsEmployability Skills

1.01 & 2.05 Assuming responsibility for own learning Introducing Direct and Indirect Relationships


Law

1.01 & 2.05 Persisting until job is completed1.01 & 2.05 Working independently

Developing career interest/goals1.01 & 2.05 Responding to criticism or questions

Information-retrieval SkillsSearching for information via the computerSearching for print informationSearching for information using community members

Language Skills - Reading2.05 Following written directions Most of the activities can

be presented as opportunities for students to follow written directions. The teacher will have to work with most students to develop this skill over time. The following activities are well suited to developing skills in following directions:

KMT Practice Questions





Law Ideal Gas law

Problems Dalton’s Law

Practice Problems

2.05 Identifying cause and effect relationships Introducing Direct and Indirect Relationships


LawSummarizing main points after readingLocating and choosing appropriate reference materialsReading for personal learning

Language Skill - WritingUsing language accurately

1.01 & 2.05 Organizing and relating ideas when writing



Law1.01 & 2.05 Proofing and Editing

Synthesizing information from several sourcesDocumenting sourcesDeveloping an outline

1.01 & 2.05 Writing to persuade or justify a positionCreating memos, letters, other forms of correspondence

Teamwork1.01 & 2.05 Taking initiative1.01 & 2.05 Working on a team

Thinking/Problem-Solving SkillsIdentifying key problems or questions

1.01 & 2.05 Evaluating results


Developing strategies to address problemsDeveloping an action plan or timeline

ENGAGE: (30 Minutes)

Kinetic Molecular Theory

The teacher should use the demonstrations to pique the students’ curiosity as they are introduced to the Kinetic Molecular Theory. Introduce the Kinetic Molecular Theory with one or two demonstrations that show students that molecules move. Possible demonstrations: (adapted from http://www.iit.edu/~smile/ch93eg.html)

DEMO #1:

Fill one 600mL beaker with 500mL of cold water. Fill the other with 500mL of hot water. Set the beakers aside so that any motion in the water comes to rest. Now sprinkle equal quantities of Methylene Blue on the water in both beakers. Twenty or thirty crystal grains are all that is needed. The blue dye will diffuse through the hot water faster than it will in the cold water. Something moves the dye around so it gets spread out evenly throughout both beakers. However the spreading out, mixing, or diffusing is not done at the same rate of speed. Hot water gets the mixing done faster than cold.

Give each student a wide rubber band and have them hold it close to their upper lip. Instruct the students to quickly pull the rubber band apart and immediately place it against their upper lip. The rubber band should feel warm. Instruct the students to bring the ends of the rubber band back together, and once again hold it against their lip. The rubber band feels cooler.

Explanation:The rubber band got hotter or cooler depending on the speed of the molecules that made it up. When we stretched out the rubber band we decreased the volume for the molecules, (modeled by lowering the paddle). When we allowed the rubber band to return to its original shape, we increased the volume for the molecules, (modeled by raising the paddle). When the volume of the rubber band was decreased, (stretched out), the molecules moved faster and resulted in the warmer band you felt against your lip. When the rubber band returned to its original shape, the molecules had more room. This is why they slowed and cooled down.


http://www.iit.edu/~smile/ch93eg.html

DEMO #2:

Materials:ping pong paddle and ball

Use a ping pong paddle and ball. Get the ping pong ball bouncing rhythmically between the paddle and the desk top. If you now quickly lower the paddle, you will see and hear a rapid increase in the ping pong ball collisions. If you, on the other hand, raise the paddle, the number of collisions will decrease.Relate to the students that the ping pong ball and paddle are only a model of what occurs on a molecular level in matter. If temperature is the average kinetic energy of moving molecules, then the faster the molecules move the warmer the substance gets. Conversely, the slower the molecules move the cooler the substance gets.

DEMO #3:You are invited to an M. C. Hammer concert. During the concert Hammer says he is going to test a new men's cologne called "Hammer". He has secretly hidden the cologne under one section of seats and in order to see how strong it is, will perform the following test at the concert:

1. The cologne is opened in one section of the stands.2. As soon as you smell the cologne raise your hand.3. Time how long the cologne odor takes to travel to all concert goers.

Your challenge is to draw a diagram to show how the concert goers will raise their hands. In addition to the diagram, tell me how the molecular kinetic theory causes the molecules to move. How will the results of Hammer's test be affected by the temperature at the concert? Will it make a difference if he has an indoor or outdoor concert?

EXPLAIN:Have students to present their answers and diagrams to the class. Instruct them to explain their reasoning.

Enrichment Activity (SAS in School)Web Inquiry: Why do helium balloons shrink faster than air-filled balloons?http://www.sasinschool.com/ProductEntrance/Launch/launch.jsp?unit=59

Other Demo Sourceshttp://www.iit.edu/~smile/ch9707.html

Animations


http://www.iit.edu/~smile/ch9707.html

http://www.sasinschool.com/ProductEntrance/Launch/launch.jsp?unit=59

http://www.chm.davidson.edu/ChemistryApplets/KineticMolecularTheory/BasicConcepts.htmlhttp://www.preparatorychemistry.com/Bishop_KMT_frames.htmhttp://www.visionlearning.com/library/module_viewer.php?mid=120

Essential Question:How would you describe the assumption of the Kinetic Molecular Theory?

ELABORATE: (15 minutes)

Following the demonstration, the teacher should begin by discussing the assumptions of the KMT. Explain that these assumptions hold true for ideal gases. Distinguish between ideal gases and real gases and the temperature/pressure conditions for both. Complete the table during the class discussion.

Ideal Gases vs. Real Gases

Ideal Gas Real Gas

particles occupy NO volume

collisions between particles are perfectly elastic


http://www.visionlearning.com/library/module_viewer.php?mid=120

http://www.preparatorychemistry.com/Bishop_KMT_frames.htm

http://www.chm.davidson.edu/ChemistryApplets/KineticMolecularTheory/BasicConcepts.html

http://www.chm.davidson.edu/ChemistryApplets/KineticMolecularTheory/BasicConcepts.html

there are no attractive forces among particles

EVALUATE: (15 minutes)

This activity will allow students to evaluate their understanding of the Kinetic Molecular Theory with guided and independent practice. After students have completed the activity, the teacher will assess students’ understanding by going over the questions with the students.

Practice Questions: Kinetic Molecular Theory

Indicate whether, according to kinetic molecular theory, the statement is true (T) or false (F).

1. When gas molecules collide with their container, they transfer energy to T Fit that is proportional to their velocity.

2. Gas molecules of different compounds have the same average kinetic T Fenergy at the same temperature.

3. Gas molecules of different compounds have the same average velocity T Fat the same temperature.

4. When two gas molecules collide, they don’t usually form a new T Fcompound.

5. Gas molecules aren’t very attracted to one another under T F standard conditions.

6. A pure sample of gas molecules will have the same average kinetic T Fenergy at all temperatures and pressures.

7. The average kinetic energy of gas molecules depends on both T Fsurrounding temperature and the molecular weight.


Additional Questionshttp://misterguch.brinkster.net/kineticmoleculartheory.pdf


Temperature and Pressure Conversion PowerPoint:

The teacher will need to reinforce temperature conversions from Unit 1 and conversion factors. The PowerPoint provides examples and practice problems. The teacher will use the PowerPoint to show students how to perform Celsius/Kelvin temperature conversions and pressure conversions.Include in the discussion:

Where to go on the Chemistry Reference Tables to find the equation for converting Celsius to Kelvin.

Where to find information relating to pressure conversions in their Chemistry Reference Tables.

Essential Question:What information do you need to perform pressure and temperature conversions?


Language (ELP) Objectives for LEP Students: Verbally or written in paragraph form, describe the process of

converting temperatures from Celsius to Kelvin and give specific examples.

Verbally or written in paragraph form explain the process of pressure conversion

http://misterguch.brinkster.net/kineticmoleculartheory.pdf

Slide 2

Slide 3


EXPLORE: (30 minutes)

Direct and Indirect Relationships

This activity is designed for students to explore the relationship between volume and pressure (Boyle’s Law) and volume and temperature (Charles’ Law). The students will make graphs from data provided.

Essential Questions:How would you describe the relationship between volume and pressure of a gas?How would you describe the relationship between volume and temperature of a gas?


Part 1. Graph the following pressure vs. volume data. Make your graph as large as possible. Title your graph and label each axis with the proper variable and unit.


Language (ELP) Objectives for LEP Students: In paragraph form, compare and contrast Boyle’s Law and Charles’ Law.

Give specific examples for each law. Discuss in paragraph form and with a partner the direct vs. indirect

relationships and how those relationships relate to the gas laws.

Volume (mL)

Pressure (psi)

29.60 17.3825.00 20.5819.20 26.8014.40 35.739.60 53.59

Part 2. Convert the temperature in oC to Kelvin (K = oC + 273). Graph the temperature in Kelvin vs. volume data. Make your graph as large as possible. Title your graph and label each axis with the proper variable and unit.

Temperature(oC)

Temperature(Kelvin)

Volume(cm3)

320 27.9338 29.5388 33.8262 22.9235 20.5

Part 3: Cause & Effect

1. Write a cause and effect statement that describes what happens to the volume of a gas when the pressure is changed.

2. Write a cause and effect statement that describes what happens to the volume of a gas when the temperature is changed.

3. Predict what would happen to the volume of a gas when the pressure is doubled.

4. Predict what would happen the pressure of a gas when the volume is reduced by 1/3.

5. Predict what would happen to the volume of a gas when the temperature in Kelvin is reduced by 1/2.


6. Predict what would happen to the temperature of a gas when the volume is increased

by 3.

7. Write brief narrative (3- 4 sentences) that describes the cause and effect relationship between pressure and volume that would help someone that is not very scientifically minded to understand this relationship. BE CREATIVE!

8. Write brief narrative (3- 4 sentences) that describes the cause and effect relationship between temperature and volume that would help someone that is not very scientifically minded to understand this relationship. BE CREATIVE!

ELABORATE: (30 mins)

Boyle’s Law and Charles’ Law

The teacher should build on the previous activity by explaining the gas laws. Animation links are provided to supplement the discussion.

Provide the formula for the combined gas law and show students how to derive Boyle’s Law, Charles’, and Gas-Lussac’s Law. The focus should be placed on the relationships rather than the names.

It is important for students to know where to find the equation in the Chemistry Reference Tables.

The teacher will model for students how to solve Boyle’s law, Charles’ law and Combined Gas Law problems.

Animations on the Web:

Boyle’s Law http://www.lerc.nasa.gov/WWW/K-12/airplane/aboyle.html

Charles’ Law http://www.lerc.nasa.gov/WWW/K-12/airplane/aglussac.html

Essential Question:How are the pressure, volume, and temperature of a gas related?


Language (ELP) Objectives for LEP Students: Describe Boyle’s Law and Charles Law in students’ own words and

provide specific examples of each law.

http://www.lerc.nasa.gov/WWW/K-12/airplane/aglussac.html

http://www.lerc.nasa.gov/WWW/K-12/airplane/aboyle.html

EVALUATE:

The practice problems will allow students to evaluate on their understanding of Boyle’s law, Charles’ law and the Combined gas law with guided and independent practice. After students have completed these problems, the teacher will assess students’ understanding by going over the problems with the students.

Essential Question:How are the pressure, volume, and temperature of a gas related?

Boyle’s Law Worksheet

Abbreviationsatm - atmospheremm Hg - millimeters of mercurytorr - another name for mm HgPa - Pascal (kPa = kilo Pascal)K - Kelvin°C - degrees Celsius

ConversionsK = °C + 2731 cm3 (cubic centimeter) = 1 mL (milliliter)1 dm3 (cubic decimeter) = 1 L (liter) = 1000 mL

Standard Conditions0.00 °C = 273 K1.00 atm = 760.0 mm Hg = 101.325 kPa = 101,325 Pa

Example #1: 2.00 L of a gas is at 740.0 mmHg pressure. What is its volume at standard pressure?

Answer: this problem is solved by inserting values into P1V1 = P2V2.

(740.0 mmHg) (2.00 L) =(760.0 mmHg) (x)


Language (ELP) Objectives for LEP Students: Describe Boyle’s Law and Charles Law in students’ own words and

provide specific examples of each law.

Problems:

1. A gas occupies 12.3 liters at a pressure of 40.0 mm Hg. What is the volume when the pressure is increased to 60.0 mm Hg?

2. If a gas at 25.0 °C occupies 3.60 liters at a pressure of 1.00 atm, what will be its volume at a pressure of 2.50 atm?

3. A gas occupies 1.56 L at 1.00 atm. What will be the volume of this gas if the pressure becomes 3.00 atm?

4. A gas occupies 11.2 liters at 0.860 atm. What is the pressure if the volume becomes 15.0 L?

5. 500.0 mL of a gas is collected at 745.0 mm Hg. What will the volume be at standard pressure?

6. Convert 350.0 mL at 740.0 mm of Hg to its new volume at standard pressure.

7. Convert 338 L at 63.0 atm to its new volume at standard pressure.

Charles’ Law Practice




Example #1: 4.40 L of a gas is collected at 50.0°C. What will be its volume upon cooling to 25.0°C?


First of all, 2.20 L is the wrong answer. Sometimes a student will look at the temperature being cut in half and reason that the volume must also be cut in half. That would be true if the temperature was in Kelvin. However, in this problem the Celsius is cut in half, not the Kelvin.

Answer: convert 50.0°C to 323 K and 25.0°C to 298 K. Then plug into the equation and solve for x, like this:

1. Calculate the decrease in temperature when 2.00 L at 20.0 °C is compressed to 1.00 L.

2. 600.0 mL of air is at 20.0 °C. What is the volume at 60.0 °C?

3. A gas occupies 900.0 mL at a temperature of 27.0 °C. What is the volume at 132.0 °C?

4. What change in volume results if 60.0 mL of gas is cooled from 33.0 °C to 5.00 °C?

5. Given 300.0 mL of a gas at 17.0 °C. What is its volume at 10.0 °C?

6. A gas occupies 1.00 L at standard temperature. What is the volume at 333.0 °C?

7. At 27.00 °C a gas has a volume of 6.00 L. What will the volume be at 150.0 °C?

8. At 225.0 °C a gas has a volume of 400.0 mL. What is the volume of this gas at 127.0 °C?

Combined Gas Law Practice

Example #1: This type of combined gas law problem (where everything goes to STP) is VERY common:

2.00 L of a gas is collected at 25.0°C and 745.0 mmHg. What is the volume at STP?

STP is a common abbreviation for "standard temperature and pressure."

You have to recognize that five values are given in the problem and the sixth is an x. Also, remember to change the Celsius temperatures to Kelvin.


When problems like this are solved, I write a solution matrix, like this:

and fill it in with data from the problem.

Here is the right-hand side filled in with the STP values:

You can be pretty sure that the term "STP" will appear in the wording of at least one test question. It is recommended that you memorize the various standards conditions. Here's the solution matrix completely filled in:

Insert the values in their proper places in the combined gas law equation:

P1V1 / T1 = P2V2 / T2

and solve for x.

Problems:





1. A gas has a volume of 800.0 mL at minus 23.00 °C and 300.0 torr. What would the volume of the gas be at 227.0 °C and 600.0 torr of pressure?

2. 500.0 liters of a gas are prepared at 700.0 mm Hg and 200.0 °C. The gas is placed into a tank under high pressure. When the tank cools to 20.0 °C, the pressure of the gas is 30.0 atm. What is the volume of the gas?

3. What is the final volume of a 400.0 mL gas sample that is subjected to a temperature change from 22.0 °C to 30.0 °C and a pressure change from 760.0 mm Hg to 360.0 mm Hg?

4. What is the volume of gas at 2.00 atm and 200.0 K if its original volume was 300.0 L at 0.250 atm and 400.0 K.

5. At conditions of 785.0 torr of pressure and 15.0 °C temperature, a gas occupies a volume of 45.5 mL. What will be the volume of the same gas at 745.0 torr and 30.0 °C?

6. A gas occupies a volume of 34.2 mL at a temperature of 15.0 °C and a pressure of 800.0 torr. What will be the volume of this gas at standard conditions?

7. The volume of a gas originally at standard temperature and pressure was recorded as 488.8 mL. What volume would the same gas occupy when subjected to a pressure of 100.0 atm and temperature of minus 245.0 °C?

8. At a pressure of 780.0 mm Hg and 24.2 °C, a certain gas has a volume of 350.0 mL. What will be the volume of this gas under STP


In this activity, students will explore pressure volume relationships as they collect data using the Calculator-Based Labs by Vernier. The student will manipulate the volume of a certain amount of air and determine how the pressure is affected by these changes in volume. A graph will be generated on the calculator.

Students will see how to generate the graph experimentally and find that the relationship between volume and pressure is inverse as previously discussed.


After the activity, the teacher should tie this lab back to the activity “Direct and Indirect Relationships.”

Essential Question: How would you describe the relationship between volume and pressure?

Boyle’s Law: Pressure-VolumeRelationship in Gases

© 2008 Vernier Software & Technology

The primary objective of this experiment is to determine the relationship between the pressure and volume of a confined gas. The gas we use will be air, and it will be confined in a syringe connected to a Pressure Sensor (see Figure 1). When the volume of the syringe is changed by moving the piston, a change occurs in the pressure exerted by the confined gas. This pressure change will be monitored using a Pressure Sensor. It is assumed that temperature will be constant throughout the experiment. Pressure and volume data pairs will be collected during this experiment and then analyzed. From the data and graph, you should be able to determine what kind of mathematical relationship exists between the pressure and volume of the confined gas. Historically, this relationship was first established by Robert Boyle in 1662 and has since been known as Boyle’s law.

Figure 1

MATERIALSLabPro or CBL 2 interface DataMate ProgramTI Graphing Calculator 20-mL gas syringeVernier Gas Pressure Sensor or Pressure Sensor

PROCEDURE1. Prepare the Pressure Sensor and an air sample for data collection.

a. Plug the Pressure Sensor into Channel 1 of the LabPro or CBL 2 interface. Use the link cable to connect the TI Graphing Calculator to the interface. Firmly press in the cable ends.


b. With the 20-mL syringe disconnected from the Pressure Sensor, move the piston of the syringe until the front edge of the inside black ring (indicated by the arrow in Figure 1) is positioned at the 10.0 mL mark.

c. Attach the 20-mL syringe to the valve of the Pressure. Newer Vernier Gas Pressure Sensors have a white stem protruding from the end of the sensor box—attach the syringe directly to the white stem with a gentle half-turn. Older Vernier Pressure Sensors have a 3-way valve at the end of a plastic tube leading from the sensor box. Before attaching the 20-mL syringe, align the blue handle with the stem of the 3-way valve that will not have the syringe connected to it, as shown in the figure at the right—this will close this stem. Then attach the syringe directly to the remaining open stem of the 3-way valve.

2. Turn on the calculator and start the DATAMATE program. Press CLEAR to reset the program.

3. Set up the calculator and interface for a Gas Pressure Sensor or Pressure Sensor.a. Select SETUP from the main screen.b. If the calculator displays a Pressure Sensor set to kPa in CH 1, proceed

directly to Step 4. If it does not, continue with this step to set up your sensor manually.

c. Press ENTER to select CH 1. d. Select PRESSURE from the SELECT SENSOR menu. e. Select the correct pressure sensor (GAS PRESSURE SENSOR or

PRESSURE SENSOR) from the PRESSURE menu.f. Select the calibration listing for units of (KPA).

4. Set up the data-collection mode.a. To select MODE, press once and press ENTER .b. Select EVENTS WITH ENTRY from the SELECT MODE menu.c. Select OK to return to the main screen.

5. You are now ready to collect pressure and volume data. It is best for one person to take care of the gas syringe and for another to operate the calculator.a. Select START to begin data collection.b. Move the piston so the front edge of the inside black ring (see Figure 2) is

positioned at the 5.0-mL line on the syringe. Hold the piston firmly in this position until the pressure value displayed on the calculator screen stabilizes.

c. Press ENTER and type in “5”, the gas volume (in mL) on the calculator. Press ENTER to store this pressure-volume data pair.


Figure 2d. To collect another data pair, move the syringe to 7.5 mL. When the

pressure reading stabilizes, press ENTER and enter “7.5” as the volume.e. Continue with this procedure using volumes of 10.0, 12.5, 15.0, 17.5, and

20.0 mL. f. Press STO when you have finished collecting data.

6. Examine the data pairs on the displayed graph. As you move the cursor right or left, the volume (X) and pressure (Y) values of each data point are displayed below the graph. Record the pressure (round to the nearest 0.1 kPa) and volume data values in your data table.

7. Based on the graph of pressure vs. volume, decide what kind of mathematical relationship exists between these two variables, direct or inverse. To see if you made the right choice:a. Press ENTER , then select ANALYZE from the main screen.b. Select CURVE FIT from the ANALYZE OPTIONS menu.c. Select POWER (CH 1 VS ENTRY) from the CURVE FIT menu. The linear-

regression statistics for these two lists are displayed for the equation in the form

y = ax^bwhere x is volume, y is pressure, a is a proportionality constant, and b is the

exponent of x (volume) in this equation. Note: The relationship between pressure and volume can be determined from the value and sign of the exponent, b.

d. To display the regression curve on the graph of pressure vs. volume, press ENTER . If you have correctly determined the mathematical relationship, the power regression line should very nearly fit the points on the graph (that is, pass through or near the plotted points).

8. (optional) Print a graph of pressure vs. volume, with a regression line displayed.

9. (optional) If directed by your instructor, proceed directly to the Extension that follows Processing the Data.


DATA and Calculations

PROCESSING THE DATA1. If the volume is doubled from 5.0 mL to 10.0 mL, what does your data show

happens to the pressure? Show the pressure values in your answer.

2. If the volume is halved from 20.0 mL to 10.0 mL, what does your data show happens to the pressure? Show the pressure values in your answer.

3. If the volume is tripled from 5.0 mL to 15.0 mL, what does your data show happened to the pressure? Show the pressure values in your answer.

4. From your answers to the first three questions and the shape of the curve in the plot of pressure versus volume, do you think the relationship between the pressure and volume of a confined gas is direct or inverse? Explain your answer.

5. Based on your data, what would you expect the pressure to be if the volume of the syringe was increased to 40.0 mL. Explain or show work to support your answer.

6. Based on your data, what would you expect the pressure to be if the volume of the syringe was decreased to 2.5 mL.

7. What experimental factors are assumed to be constant in this experiment?

8. One way to determine if a relationship is inverse or direct is to find a proportionality constant, k, from the data. If this relationship is direct, k = P/V. If it is inverse, k = P•V. Based on your answer to Question 4, choose one of these formulas and calculate k for the seven ordered pairs in your data table (divide or multiply the P and V values). Show the answers in the third column of the Data and Calculations table.

9. How constant were the values for k you obtained in Question 8? Good data may show some minor variation, but the values for k should be relatively constant.


Volume(mL)

Pressure(kPa)

Constant, k(P / V or P • V)

10.Using P, V, and k, write an equation representing Boyle’s law. Write a verbal statement that correctly expresses Boyle’s law.

EXTENSION1. To confirm that an inverse relationship exists between pressure and volume,

a graph of pressure vs. reciprocal of volume (1/volume or volume-1) may also be plotted. To do this using your calculator:a. Press ENTER , then return to the main screen. b. Select QUIT to quit DATAMATE program. (Then press ENTER on a TI-83

Plus or TI-73). c. Create a new data list, reciprocal of volume, based on your original volume

data.

TI-73 Calculatorsd. To view the data lists, press LIST .e. Move the cursor up and to the right until the L3 heading is highlighted. f. Create a list of 1/volume values in L3. First press 2nd [STAT], and select

L1. Then press 2nd [x–1] ENTER .

TI-83 and TI-83 Plus Calculatorsd. To view the data lists, press STAT to display the EDIT menu, and select

Edit.e. Move the cursor up and to the right until the L3 heading is highlighted. f. Create a list of 1/volume values in L3 by pressing 2nd [L1] x–1 ENTER .

TI-86 Calculatorsd. To view the data lists, press 2nd [STAT] and select <EDIT>.e. Move the cursor up and to the right until the L3 heading is highlighted. f. Create a list of 1/volume values in L3 by pressing <NAMES> <L1> 2nd

[x–1] ENTER .g. Press 2nd [QUIT] when you are finished with this step.

TI-89, TI-92, and TI-92 Plus Calculatorsd. Press APPS , then select Home.e. On a TI-89 calculator, create a list of 1/volume values in L3 by pressing

CLEAR 1 ALPHA [L] 1 STO ALPHA [L] 3 ENTER . On a TI-92 or TI-92 Plus, press CLEAR 1 L 1 STO L 3 ENTER

.

2. Follow this procedure to calculate regression statistics and to plot a best-fit regression line on your graph of pressure vs. 1/volume:

a. Restart the DATAMATE program. b. Select ANALYZE from the main screen.c. Select CURVE FIT from the ANALYZE OPTIONS menu.


d. Select LINEAR (CH1 VS CH2). Note that CH1 is pressure and CH2 is 1/volume. The linear-regression statistics for these two lists are displayed for the equation in the form:

y = ax + bwhere x is 1/volume, y is pressure, a is a proportionality constant, and b is the

y-intercept.e. To display the linear-regression curve on the graph of pressure vs.

1/volume, press ENTER . If the relationship between P and V is an inverse relationship, the plot of P versus 1/V should be direct; that is, the curve should be linear and pass through (or near) the origin. Examine your graph to see if this is true for your data.

3. (optional) Print a copy of the graph of pressure vs. 1/volume, with the linear regression curve displayed.

NOTE: For those who do not have access to the CBL materials in order to do the above activity with their classes, an alternate activity follows:

Alternative to Boyle’s Law CBL Lab

The teacher should provide the Data Set to students. Students should be instructed to graph the data manually or input the data into graphing calculators or Excel and generate a graph. Students should be asked to analyze the data to determine the relationship between volume and pressure.

Trial Pressure Volume1 100 kPa 40 cm3

2 50 kPa 80 cm3

3 200 kPa 20 cm3

4 400 kPa 10 cm3

5 25 kPa 160 cm3

EXPLAIN:

Have students to present their answers to Processing the Data to the class. Instruct them to explain their reasoning.


Ideal Gas Law

In this activity, students will EXPLORE the graphical relationships among the following data:

o pressure vs. volumeo volume vs. temperatureo pressure vs. temperature


o volume vs. moles

The teacher should choose between Option 1 and Option 2 for this activity. Option 1 is a computer-based activity that requires internet access through SAS in Schools. In Option 2, the teacher provides sample data rather than obtaining it through the SAS activity.

Essential Question:How are the pressure, volume, temperature, and moles of a gas related?

Option 1 Collect pressure, volume, temperature, and mole data using the SAS in

Schools Gas Law Interactivity. This may be done as a class or individually depending on computer availability.

o http://www.sasinschool.com/ProductEntrance/Launch/launch.jsp? unit=8

o Students will place data in the data table and generate a graph for each experiment.

o Students will answer the questions and complete the analysis table.o Following the activity, the teacher should help the students derive

the Ideal Gas Equation.

Option 2 In option 2, the teacher will provide the data for the table rather than using

SAS to collect the data. Sample data is provided below:

Data TableGas Identity: Argon

TrialExperiment 1 Experiment 2 Experiment 3 Experiment 4Pressure(atm)

Vol.(L)

Volume(L)

Temp.(K)

Pressure(atm)

Temp.(K)

Volume(L)

Quantity(moles)

1 0.9 25 23 250 0.90 500 46 1.002 0.8 28 18 200 0.80 450 41 0.903 0.7 32 27 300 0.50 275 37 0.804 1.1 20 37 400 0.95 525 32 0.705 1.2 19 41 450 0.85 475 29 0.656 1.4 16 46 500 0.75 425 34 0.75


Language (ELP) Objectives for LEP Students: Explain verbally or in written form the difference between the following:

pressure vs. volume volume vs. temperature pressure vs. temperature volume vs. moles



Ideal Gas LawData TableGas Identity: Helium

TrialExperiment 1 Experiment 2 Experiment 3 Experiment 4Pressure(atm)

Vol.(L)

Volume(L)

Temp.(K)

Pressure(atm)

Temp.(K)

Volume(L)

Quantity(moles)

1 0.75 34 22 400 1.1 550 30 0.752 0.85 30 19 350 0.9 450 38 0.933 1.10 23 15 275 0.8 400 45 1.10

Graph the data from the table for each Experiment.

Questions:a. What does each graph indicate about the relationship between the variables?b. For each pair of variables, write a statement that describes their relationship and indicates the conditions for validity. For example, x and y are directly proportional, if a and b remain constant.c. The four relationships you just described are expressed as laws. Using the following information, label each statement from questions b with its correct name (Avogadro’s law, Boyle’s law, or Charles’ law, and Gay-Lussac’s law.)

Analysis Table Trial P x V

(Pressure times volume)

V/T(Volume divided by temperature)

P/T(Pressure divided by temperature)

V/n(Volume divided by gas quantity)

1

2

3

4

5

6


ELABORATE:

After completing Option 1 or Option 2, the teacher should show students where the Ideal Gas Law is located in their Chemistry Reference Tables.

Be sure to show students where to find the values for Standard Temperature & Pressure and Gas Constant are on their Chemistry Reference Tables.

Model for students how to work problems with different pressure units, showing students the use of the three gas constant values.

Animation web links are provided to supplement the discussion.

Ideal Gas Law http://www.lon-capa.org/~mmp/applist/pvt/pvt.htmhttp://www2.wwnorton.com/college/chemistry/gilbert/tutorials/ch8.htm



The Ideal Gas Law Problems will allow students to evaluate their understanding of the Ideal gas law with guided and independent practice. After students have completed these problems, the teacher will assess students’ understanding by going over the problems with the students.


Ideal Gas Law Problems

1. A chemical reaction produces 0.0680 mol of oxygen gas. What volume in liters is occupied by this gas sample at STP?

2. A chemical reaction produced 98.0 mL of sulfur dioxide at STP. What was the mass (in grams) of the gas produced?

3. What is the pressure in mm Hg exerted by a 0.500 mol sample of nitrogen gas in a 10.0 L container at 25oC?

4. What mass of chlorine gas, in grams, is contained in a 10.0 L tank at 27oC and 3.50 atm of pressure?

5. How many moles of oxygen gas, O2, are contained in 750.0 cm3 at 27oC and a pressure of 1.2 atm?


http://www2.wwnorton.com/college/chemistry/gilbert/tutorials/ch8.htm

http://www.lon-capa.org/~mmp/applist/pvt/pvt.htm

6. A sample of hydrogen iodide occupies 400.0 cm3 at STP. How many moles are in the sample?

7. At 0oC, 0.75 moles of a gas occupies a volume of 5 L. What is the pressure (in kPas) exerted by the gas?

8. 1.5 L of gas exerts a pressure of 96.8 kPa at 12oC. How moles of the gas are in the sample?

Ideal Gas Law Practice

http://dbhs.wvusd.k12.ca.us/webdocs/GasLaw/WS-Ideal.htmlhttp://chemsite.lsrhs.net/gasses/handouts/Ideal_Problems.pdf

Interactive Ideal Gas Law Calculations

http://www.ausetute.com.au/idealgas.html

ENGAGE: (15 minutes)

The Dalton’s Law Demonstration should use this demonstration to engage students as they are introduced to the Dalton’s Law of Partial Pressures.

Essential Question:How is the total pressure of a sample of gases related to the partial pressure of each gas in the sample?

Dalton’s Law Demonstration

Materials:Erlenmeyer flask one hole stopper glass tubing (bent)Rubbing tubing large test tube large container of water3M HCl Zinc (mossy) index card

Procedure:


Language (ELP) Objectives for LEP Students: In paragraph form, summarize the teacher demonstration for collecting a gas

over water. Use key vocabulary terms. Describe what you need to do to find vapor pressures and appropriate

temperatures for solving the gas law problems.

http://www.ausetute.com.au/idealgas.html

http://chemsite.lsrhs.net/gasses/handouts/Ideal_Problems.pdf

http://dbhs.wvusd.k12.ca.us/webdocs/GasLaw/WS-Ideal.html

1. Fill a large container with water. Fill a test tube to the rim with water. Place the index card over the test tube and invert into the large container of water. Remove the index card. If any air bubbles gets into the test tube, try again.

2. In the Erlenmeyer flask, conduct a reaction between one piece of zinc and HCl. Stopper the flask with the rubber tubing.

3. Insert the rubber tubing in the test tube and allow the H2 gas to displace the water. This will show students how a gas can be collected over water.

4. Ignite the gas. There will be a small “poof”.

Following the demonstration, the teacher should explain to students that gas collection over water is an essential technique used when studying Dalton’s Law.This will serve as transition to the next segment of the lesson (ELABORATE).


The teacher should then introduce and explain Dalton’ Law of Partial Pressures. It is important to show students where the equation for Dalton’s law is located in the Chemistry Reference Tables. The teacher should instruct students how to solve Dalton’s law problems by working examples of partial pressure problems including solving problems for gases collected over water. Students will need to understand where to find vapor pressures at certain temperatures when working these problems. There will be chart in the textbook. When showing student s the chart, make sure they understand the relationship between temperature and vapor pressure.



The Dalton’s Law of Partial Pressures activity will allow students to evaluate their understanding of the Ideal gas law with guided and independent practice. After students have completed these problems, the teacher will assess students’ understanding by going over the problems with the students.



Dalton’s Law Problems

1. A mixture of neon and argon gases exerts a total pressure of 2.39 atm. The partial pressure of the neon alone is 1.84 atm, what is the partial pressure of the argon?

2. A 450 cm3 sample of hydrogen is collect over water at 12oC. The pressure of the hydrogen and water vapor mixture is 78.5 kPa. What is the partial pressure of the dry hydrogen gas? (look up the vapor pressure of water at 12oC)

3. 888 cm3 of oxygen are collected over water with a temperature of 27oC. The total pressure of the gases is 55.8 kPa. What is the partial pressure of the dry gas?

4. What is the total pressure of a mixture of gases made up of CO2, O2 and H2 if the partial pressures are 22.3 kPa, 44.7 kPa and 112 kPa respectively?

5. A quantity of Helium is collected over water at 70oC, and the mixture has a pressure of 89.9 kPa. What is the partial pressure of the water vapor?

6. A sample of hydrogen is collected by displacing a sample of water with a temperature of 35oC. The mixture has a total pressure of 114 kPa. What is the partial pressure of the dry hydrogen?

A web resource is provided for additional student practice.

Dalton’s Law Practice

http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson74.htmhttp://dbhs.wvusd.k12.ca.us/webdocs/GasLaw/WS-Dalton.html


http://dbhs.wvusd.k12.ca.us/webdocs/GasLaw/WS-Dalton.html

http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson74.htm

EVALUATE:Sample Assessment Questions for Unit 10Unit Goal/

RBT Tag

Questions

10 2.05

C3

C3

1. A 2.00 L flask is filled with propane gas, C3H8, at 1.00 atm and -15.0 oC. What is the mass of the propane in the flask?

A. 3.72 gB. 4.16 gC. 71.5 g D. 466.0 G

2. A sample of nitrogen gas is stored in 500.0 mL flask at 108 kPa and 10 oC. The gas is transferred to a 750.0 mL flask at 21 oC. What is the pressure of the nitrogen gas in the second flask?

A. 69.3 kPaB. 74.8 kPaC. 151.2 kPaD. 112.2 kPa


Following are sample test items obtained from the WIZARD test bank developed by eduware™ that can be used to allow students to assess their understanding and abilities and allow the teacher to evaluate the students understanding of key concepts and skill development for this unit.


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