Chemistry Themed

Gas Laws and Gas Stoichiometry

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Chemistry in the Community

Air: Gas Laws and Gas Stoichiometry 2015-2016 Date In-Class Assignment Homework R 12/3 Turn In Cu Unlimited

Gas Conversions pkt p 7 Mathematical Relationships, DATA Pkt p 9 pressure versus volume

Complete Pressure Calculations pkt p 7 Developing Skills A.6, p 164-165 #1-3

F 12/4 Mathematical Relationships, DATA Pkt p 10-11, pressure vs. temperature Mathematical Relationships, DATA Pkt p 12, volume vs. temperature http://intro.chem.okstate.edu/1314F00/Laboratory/GLP.htm

Developing Skills A.11, p 172-173 Do ONLY 1, 2, 4 Developing Skills A.13, p 174-175 Do ONLY 1, 3, 5

M 12/7

Go over homework Putting It All Together: The Gas Laws pkt p 13 The Combined Gas Law; pkt p 14

Complete Gas Law problems, pkt p 15-16

T 12/8

Go over homework Molar Conversions Worksheet, pkt p 17 Jumping Jack Flash and STP, Ideal Gas Law Pkt p 18

Ideal Gas Law Problems Pkt p 19 Read Section B.4 p 186-187; fill in top of pkt p 20

W 12/9

Go over Ideal Gas Law Problems REVISIT STOICHIOMETRY Go over packet p 20 Do packet p 20-21 as a class Work on pkt p 22-23

Combined and Ideal Gas Law Problems, pkt p 24-25

R 12/10

Review for tomorrow’s test! Discuss Courses for Next Year

STUDY FOR TEST

F 12/11 TEST on Gas Laws and Gas Stoichiometry

M 12/14 Work on Semester Exam 1st Semester Review Guide

Study for Final

T 12/15 Work on Semester Exam 1st Semester Review Guide

Study for Final Complete Review Guide

W 12/16 Final Exams: Periods 3, 4/5 R 12/17 Final Exams: Periods 2, 10, 7/8 F 12/18 Final Exams: Periods 1, 9

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Chemistry Name: _______________________________ Period: _________

Gas Laws and Gas Stoichiometry: Objectives Checklist

My action plan to help me improve my learning includes: Review labs, notes, packet and activities.

Use the calendar to make sure everything is reviewed.

Ask and answer questions during class.

Have a family member or friend quiz me orally.

Start studying early! (Not just the night before the test.)

Meet with my teacher in the morning/afterschool for extra help.

Re-read or review all assigned sections from the book.

Use the magic calculator online to check your calculation answers to appropriate labs.

Do online practice quizzes available through class website or through internet.

Complete and review homework problems by reworking them and NOT just looking at them.

Find a study buddy from Chemistry who understands the material and I can work well with.

Use Objective Checklist throughout unit to assess understanding

Use Objective Checklist as a study guide

Use this checklist as your personal guide to assess your level of readiness for quizzes and the unit test. Circle the descriptor that best describes how you feel about your mastery of each objective. NOTE: IF IT IS NOT A , YOU PROBABLY ARE NOT READY FOR THE QUIZ/TEST!!!!!

= I get it ? = I need more practice/review ! = I need to get help

During Unit Before Test (An asterisk indicates an overarching theme from a past unit!)

I feel confident that I…

  ?  !        ?  !  1. … Can write relationship equations based on lab or computer generated data for gas law data or other data. 

  ?  !        ?  !   

2. … Can graphically represent the relationship between P & V; V & T; and P & T. 

  ?  !        ?  !   

3. … Can convert degrees Celsius to Kelvin and understand what absolute zero is and understand why the Kelvin scale is used with gases. 

  ?  !        ?  !  4. …  Know how to solve problems using the combined gas law. 

  ?  !        ?  !   

5. … Know how to solve problems using the ideal gas law and the ideal gas law constant. 

  ?  !        ?  !   

6. … Know what STP is and the values that correspond with it. 

  ?  !        ?  !  7. … Understand Molar Volume. 

  ?  !        ?  !   

8. … Can solve problems using gas stoichiometry. 

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Check off the study skills you USED to move from ? or ! to while studying for the test.

I have carefully self-assessed my work during this unit and have taken steps to get my questions answered before the quiz/test. Student Signature: ____________________________________________________ Parent Signature: _____________________________________________________ Date: ____________________________________________________

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Pressure Conversions Use the following known pressure conversions to complete the following problems. 1 atm = 760 mmHg = 760 Torr = 101.3 kPa = 14.7 psi 1. 2.76 atm to psi 2. 985 mmHg to atm 3. 21.5 psi to mmHg 4. 110 Torr to mmHg

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Mathematical Relationships of KMT

1. PRESSURE vs VOLUME Based on your knowledge from KMT or the Human Gas Particle Activity, state the relationship between pressure and volume of a sample of gas (at constant temp).

Your teacher will show you a demonstration of a sample of gas trapped in a syringe that is hooked up to a pressure meter. Record the results of the pressure for each volume tested .

Volume (mL) (syringe + tube)

Pressure (P x V) P/V

5.0 + 1.3 = 6.3 mL

7.5 + 1.3 = 8.8 mL

10.0 + 1.3 = 11.3 mL

12.5 + 1.3 = 13.8 mL

15.0 + 1.3 = 16.3 mL

17.5 + 1.3 = 18.8 mL

20.0 + 1.3 = 21.3 mL

Prepare a graph below plotting pressure on the y-axis vs volume on the x-axis

To look for a mathematical relationship between Pressure and Volume, fill in the last two columns of the chart. In the second to last column, multiply Pressure times Volume; in the final column, divide Pressure by Volume. Which calculation gives you a CONSTANT number? _____________________________

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2. PRESSURE vs TEMPERATURE

Based on your knowledge from KMT or the Human Gas Particle Activity, state the relationship between pressure and temperature of a sample of gas (at constant volume).

Your teacher will show you a demonstration of a sample of gas trapped in a syringe that is hooked up to a pressure meter. Record the results of the pressure for each volume tested .

Type of “bath” Temp o C Pressure P/T (P x T) Dry ice and Ethanol

Ice and water

Room temp

warm water

To look for a mathematical relationship between Pressure and Temperature, fill in the last two columns of the chart. In the second to last column, multiply Pressure times Temperature; in the final column, divide Pressure by Temperature.

Which calculation gives you a CONSTANT number? _____________________________

Prepare a graph below plotting pressure vs temperature on the x-axis. USE THE TEMP SCALE AS IS!

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The reason why you did not get a CONSTANT value for either of your calculations is that you had both positive and negative values for your temperature. This led chemists to devise a temperature scale that has NO NEGATIVE NUMBERS!! Extrapolate your line from your graph back to a Pressure of 0. This is the Absolute Lowest the temperature you can go, because you can’t have a negative pressure. Record below what temperature this corresponds to on your graph. ____________________ °C is the absolute lowest temperature on graph Scientists have actually found Absolute Zero to be ________________________ °C This created a new temperature scale called the Kelvin temperature scale. The following formulas are used to convert degrees Celsius to Kelvins and vice versa. PRACTICE: Convert 87.3o C into Kelvins __________________________________ Convert 351 K into oC ______________________________ Using the temperature conversion formula above, recreate the Pressure/Temperature data table converting your Celsius temperature readings into Kelvin, and then perform the mathematical relationships. Type of “bath” Temp (o C) Temp (K) Pressure P/T (in K) (P x T (in K)) Dry ice and Ethanol

Ice and water

Room temp

warm water

Which calculation gives you a CONSTANT number? _____________________________

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3. TEMPERATURE vs VOLUME Based on your knowledge from KMT or the Human Gas Particle Activity, state the relationship between temperature and volume of a sample of gas (at constant pressure). Your teacher will show you a Gas simulation computer activity where you will collect data below. NOTE THAT THE TEMPERATURE IS IN KELVIN. IT MUST BE! Volume (mL)

Temperature (K) V x TK V/TK

Prepare a graph below plotting volume vs temperature on the x-axis

To look for a mathematical relationship between Volume and Temperature, fill in the last two columns of the chart. In the second to last column, multiply Pressure times Volume; in the final column, divide Pressure by Volume. Which calculation gives you a CONSTANT number? _____________________________

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4. Putting it all together!!!

Go back to each one of your relationships that gave you a constant number and rewrite them below. Pressure and Volume: Pressure and Temperature: Volume and Temperature: From this information, we can derive the Gas Laws: Boyle’s Law: Ex: If a sample of gas at constant temperature has a volume of 45 mL and a pressure of 1.09 atm, what will its new volume be if we raise the pressure to 1.73 atm? Does your answer make sense? ___________________________________________________________________________________ John’s Law: Ex: If a sample of gas at a constant volume has a temperature of 24.0° C and a pressure of 720 Torr, what will its new pressure be if we raise the temperature to 75.2o C? (HINT: don’t forget our friend Kelvin!) _______________________________________________________________________________ Charles’ Law: Ex: If a sample of gas at constant pressure has a volume of 1.89 L and a temperature of 82.9° C, what will it’s new volume be if we lower the temperature to 2.8oC?

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THE COMBINED GAS LAW! We can actually combine ALL of the laws into one, called The Combined Gas Law. The Combined Gas Law can be used in place of all the other gas laws. Ex: If a sample of gas at constant temperature has a volume of 45 mL and a pressure of 1.09 atm, what will its new volume be if we raise the pressure to 1.73 atm? Ex: A sample of a gas is at 773 mmHg, a volume of 1.3 L and a temperature of 25.2o C. If the temperature is changed to 42.1o C and the volume changed to 2.3 L, what is the new pressure in mmHg? Convert this pressure to kPascals.

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Gas Law Problems (Use T-charts and show your work!)

1. A 412 mL balloon at atmospheric pressure (1.00 atm) is placed in a vacuum jar and the air is evacuated from the jar. If the balloon enlarges to a volume of 663 mL, what is the new pressure in atm? What is the new pressure in Torr? (0.621; 472)

2. A medical syringe has a sample of gas with a volume of 2.5 cm3 at a pressure of 700 mm Hg. If the pressure

is increased to 820 mm Hg, what is the new volume in cm3? (2)

3. You need 6.22 L of SO2 gas at 0.00 °C and 1.00 atm. What would be the volume of this gas at 25.0° C and

1.00 atm? (6.79 L) 4. Suppose a tennis ball contains 119 mL of a gas and is pressurized to 32.1 psi at a temperature of 41° C.

What is the internal pressure of the ball in psi if the temperature drops to 3° C? (28.2) 5. A sample of oxygen gas is at 65°C and 3.8 atm and a volume of 23.98 L. If the volume changes to 20.21 L

and the pressure to 2.1 atm, what must the new temperature in degrees Celsius? (-110)

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6. A gas has a volume of 254 mL at 113 atm. At a pressure of 95 atm, what volume in mL will this gas

occupy? (3.0 x 102)

7. If the gas temperature inside a balloon is 44°C and its volume is 80.0 L, then what must the temperature

have been changed to in order to make the new balloon volume 21.9 L? (86.8) 8. The volume of a gas is 13.0 L at a temperature of 34.0°C and a pressure of 3.0 atm. If the pressure changes

to 1.0 atm and the temperature increases to 78.0°C, what will the new volume be in liters? (45) 9. A 25.0 L air sample at a temperature of 37.0° C has a pressure of 760 mmHg. If the temperature of the

sample is heated to 45.2° C and the pressure changes to 1.4 atm, how many liters is the new volume? (18) 10. A 3.00 L flask was used to collect a sample of butane gas at a pressure of 760 Torr and a temp of 37.0 °C.

After the sample was collected, the gas pressure was measured to 898 mmHg. What is the new temperature of the butane gas measured in Kelvins? (370)

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Grams/Moles Calculations (show all your work!)

Given the following, find the number of moles:

1. 30.4 grams of H3PO4 (0.310)

2. 25 grams of HF (1.2)

3. 110 grams of NaHCO3 (1.3)

4. 1.1 grams of FeCl3 (0.0068) Given the following, find the number of grams:

5. 4.5 moles of Cu(CN)2 (520)

6. 15.6 moles of C6H6 (1,220)

7. 21.3 moles of BaCO3 (4.20 x 103)

8. 1.2 moles of NaCl (70.)

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Jumping Jack Flash, It's a Gas, Gas Gas!!!!!

Quick, who sang that song?

Trying to describe a gas can get very complicated since you would always have to express the temperature and the pressure the gas is at. So, our friendly chemists came up with some STANDARD CONDITIONS that are used when describing gases. STP: Standard Temperature and Pressure Temperature = ______________________ Pressure = ______________________ Amadeo Avagadro determined that:

One mole of ANY gas at STP has a volume of 22.4 liters. Using these standard values, and our knowledge of the Combined Gas Law, we can calculate what is known as THE IDEAL GAS LAW CONSTANT. This constant can be used for any sample of gas at any set of conditions. PV ―— = R nT R = ______________________ THE IDEAL GAS LAW: (You must convert all variable units to the correct ones! units are very important!) Your teacher may have a way or pronouncing this law (equation) to make it easier to remember.

Sample problems using Ideal gas law Ex 1: I have 2.5 moles of oxygen at 27.1°C and a volume. What is the pressure of this sample? Ex 2: I have 42.8 g of Neon gas at 21.0° C and 142.6 kPa. What is the volume of this sample?

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Ideal Gas Law Problems

Use the ideal gas law to solve the following problems. You know that these problems need the ideal gas law because you are only given one set of conditions. Use the answers in parenthesis to help you check your answers.

Show all work including units and significant figures. You must write the equation without numbers first!

1. If a gas container has 4.00 moles of a gas at a pressure of 5.60 atm and a volume of 12.0 liters, what is the temperature? (205 K)

2. If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 31 liters, and a temperature of 87°

C, how many moles of gas do I have? (1.3 mol) 3. If there are 3.00 moles of gas in a container with a volume of 60.01iters and at a temperature of 400. K,

what is the pressure inside the container? (1.64 atm) 4. If a gas container has 7.70 moles of gas at a pressure of 0.09000 atm and temperature of 56.0° C, the what is

the volume of gas? (2310 L)

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Notes B.4 - Ideal Gases and Molar Volume

What is an ideal gas? Under what conditions will a gas not be ideal? Would a gas at absolute zero behave ideally? Read the question in Figure 2.23 on page 186 and answer it. What is Avogadro's Law? Explain how Avogadro's Law can be true for different gases? What is Molar volume? Scientists try to work with gases under the same conditions. They decided they would work with gases at 1 atm and 0°C which is called Standard Temperature and Pressure (STP)

What is the molar volume of all gases at STP? 2 H2 (g) + O2 (g) 2 H2O (g)

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What is the volume of five moles of hydrogen gas at STP? If you had 6 L (given) of H2 gas, how many L of O2 gas would react with it? How many L of H2O would be made from the above question? How many L of oxygen would react with 18.2 mol of H2 gas at STP? How many moles of H2O could be produced from 26 L of O2?

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Name: _________________________________

Period: _______ Date: ____________________

Molar Volumes Worksheet B.4

Part I: What volumes will be occupied by the following gases at STP?

1. 8.00 mol N2 2. 0.38 mol NH3 3. 3.251 mol H2 4. 218 mol O2 Part II: Balance the following equation, verify your answer with your teacher, and use it to answer the following questions. Assume the reaction occurs at STP.

CO (g) + O2 (g) CO2 (g)

1. List the number of moles of: CO __________________ O2 __________________ CO2 __________________

2. List the total number of liters of: CO __________________ O2 __________________ CO2 __________________

3. How many liters of oxygen would react with 5.3 mol of carbon monoxide? (59) 4. How many mol of carbon dioxide can be produced from 28.3 L of oxygen? (2.63) 5. How many liters of carbon monoxide would be needed to completely react with 1138 L of oxygen? (2276) 6. How many liters of carbon dioxide can be produced by the complete reaction of 18.0 L of oxygen? (36.0)

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Part III: Balance the following equation, verify your answer with your teacher, and use it to answer the following questions. Assume the reaction occurs at STP.

H2 (g) + NO2 (g) NH3 (g) 1. List the number of moles of:

H2 __________________ N2 __________________ NH3 __________________

2. List the total number of liters of: H2 __________________ N2 __________________ NH3 __________________

How many liters of 3. How many liters of ammonia can be produced from 10.1 mol of hydrogen? (151) 4. How many mol of nitrogen are required to produce 4.3 L of ammonia? (0.096) 5. How many liters of hydrogen are needed to completely react with 115 L of nitrogen? (345 ) 6. How many liters of ammonia are produced from 0.89 L of hydrogen? (0.59)

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The Ideal and Combined Gas Laws

Use your knowledge of the ideal and combined gas laws to solve the following problems. Hint: Figuring out which equation you need to use is the hard part! Use the answers in parenthesis to help you check your work.

Show all your work. Show all the equations without numbers, significant figures and units.

1. A gas takes up a volume of 17.0 L, has a pressure of 2.30 atm, and a temperature of 299 K. If I raise the temperature to 350. K and lower the pressure to 1.50 atm, what is the new volume of the gas? (30.5 L)

2. The highest pressure ever produced in a laboratory setting was about 2.0 x 106 atm. If we have a 1.0 x 10-5 L

sample of a gas at that pressure, then change the pressure until it is equal to 209 mmHg, what would the new volume of that gas be? (73 L)

3. On hot days, you may have noticed that potato chip bags seem to "inflate", even though they have not been

opened. If I have a 250.0 mL bag at a temperature of 19.0.C, and I leave it in my car which has a temperature of 60.0°C, what will the new volume of the bag be? (285 rnL)

4. A 2.2 L sample of a gas is at 18.C. If the volume is increased to 2.35L, what will the new Celsius

temperature be? (40° C (comes from 310 K))

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5. If I have 17.0 moles of gas at 67° C, and this gas occupies a volume of 88.89 L, what is the pressure of the gas? (5.34 atm)

6. A 15,000 L sample of a gas is at a pressure of 1.2 atm. The volume is changed to 19.9 L. What will the new

pressure be in kPa? (91,000 kPa)

7. A gas has a temperature of 14.0° C, and a volume of 4.50 L. If the gas temperature is raised to 29.0° C and

the pressure is not changed, then how many liters is the new gas volume? (4.74 L) 8. If I have an unknown quantity of oxygen gas at a pressure of 656 Torr, occupying a volume of 2,500 mL at

a temperature of 300. K, then how many grams of oxygen do I have? (24 g)

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