Formal Lab Report Guidelines:
All lab reports must be typed and must be turned in by the beginning of the period that they are due. THERE WILL BE ABSOLUTELY NO EXCEPTIONS!!! Spelling, grammar, punctuation, and page layout will be considered for your grade. 50 points.

Part 1: Purpose (Introduction) Tell what you are trying to prove in your lab (your hypothesis) and give a general description of how you are going to prove it (test). Include what you expect to happen if possible. You may want to give a brief introduction or add some background material about the hypothesis that you are trying to prove. .

Part 2: Materials  Give a list of all of the materials that will be needed to complete the lab. This list should be complete. Use correct names.

Part 3: Procedure Give a step-by-step description of what is to be done in the lab. Including figures may help to describe what you are trying to explain. DO NOT use “I”, “we”, or any names in the procedure. Your procedure should be specific commands and directions. Do not copy my directions unless you cite your source for the information (me). This is called plagiarism.

Part 4: Data This is where all of the information that is recorded from the experiment is provided. Give all data gathered in lab (which should be represented appropriately in charts, tables, or graphs) as well as any sample calculations required to show how mathematical data was gained. Any questions that were asked during the lab or part of the lab should be answered in this section as well.

Part 5: Conclusion This is the most important part of the lab. It should include:

a)restatement of the purpose

b)tell what you expected to happen (if possible)

c)tell what did happen

d)provide evidence to support what happened (data)

e)Conclude. Did what happen match what you expected to happen. If not, include acouple of sentences about error, where it could have occurred or did occur (if you know) as well as how to fix it for future experiments so that others may not make the same mistakes. Your conclusion should match your purpose.

I should be able to read just the conclusion and know everything about your lab.

Make sure that you get the phone number, email address, and address of your lab partner.

My email address is

*** DO NOT WAIT UNTIL THE LAST MINUTE TO TYPE YOUR PAPER.***

*** TURN THEM IN EARLY IF POSSIBLE.***

H CH 3 Homework

Problems:

1. Calculate the mass in grams of each of the following:

3.00 mols Na6.00 mols O

2. Calculate the number of moles in each of the following:

200.0 g F150.0 g Zn (SF)

3. Calculate the number of atoms in each of the following:

2.00 mols Ti46 g S

4. Calculate the number of grams of each of the following:

2.45 x 1024 atoms He (SF)7.13 x 1023 atoms U

5. 50 cm3 of silver would contain how many atoms?

6. A metal titanium rod used in repairing broken bones has a diameter of 3.50 mm and is 40 mm in length. What is its mass? How many atoms of titanium are in it?

Gas Law Problems:

1.a) 1.57 atm = _____psi

b) 880 mmHg = _____ atm

c) 1.04 x 106 Pa = _____ Torr

d) 213 mmHg = _____ Torr

Combined Gas Law:

2. A typical scuba tank has a volume of 13.2 L and a pressure of 153 atm. What volume of air in liters at .950 atm is required to fill such a scuba tank.

3. The volume of a sample of ethane ,C2H6, is 3.24 L at 477 Torr and 27 C. What volume will it occupy at 27 C and 831 Torr?

4. A gas occupies a volume of 12.5 L at STP. What volume will it occupy at 50 °C and 710 mmHg?

5. A spray can is used until it is empty except for the propellant gas which has a pressure of 1.1 atm at 23 C. If the can is thrown into a fire at 475 C, what will be the new pressure inside the can?

6. A high altitude balloon is filled with 1.41 x 104 L of hydrogen at a temperature of 21 C and a pressure of 745 Torr. What is the volume of the balloon at a height of 20 km where the temperature is -48 C and the pressure is 263.1 Torr?

Ideal Gas Law:

7. 4 moles of gas occupy a volume of 3.4 L at 35 C. What pressure is the gas under?

8. If a 114.5 L balloon is at a pressure of 1550 mmHg and contains 6 moles of helium, what temperature is the gas at?

9. What is the volume of a bulb that contains 8.17 g of neon at 13 C and a pressure of 8.73 atm?

10. How many moles of hydrogen sulfide are contained in a 327.3 mL tank at 48.1 C if the pressure is 149.3 kPa?

11. 15.50 g of an unknown gas occupies 13 L at a pressure of 770 Torr and 25 C. What is the atomic mass of the gas?

Misc:

12. What is the temperature of a .274 g sample of helium (He) confined in a 300 ml bulb at a pressure of 22 psi?

13. A cylinder of a standard gas for calibration of blood gas analyzers contains 5% CO2, 12% O2, and the remainder N2 at a total pressure of 146 atm. What is the partial pressure of each gas in the cylinder?

14. What is the volume of a sample of carbon monoxide at 3 C and 744 Torr if it occupies 13.3 L at 55 C and 22 psi?

15. A sample of oxygen occupies 38.9 L at STP. What volume will it occupy at 27 C and 831 Torr?

16. A small cylinder of helium has a volume of 334 ml. How many moles of helium are contained in the cylinder at a pressure of 154 atm and a temperature of 23 C?

17. Most mixtures of hydrogen and oxygen gas are explosive. However, a mixture that contains less than 3% O2 is not. If enough O2 is added to a cylinder of H2 at 33.2 atm to bring the total pressure to 34.5 atm, is the mixture explosive?

Review:

1. What is an ideal gas?

2. List the assumptions that the kinetic theory is based on.

3. List the properties of an ideal gas.

4. Describe the conditions under which a real gas will behave ideally.

5. If there is no such thing as an ideal gas then why do we talk about them?

6. What is pressure?

7. Why do temperature units have to be in Kelvin?

8. List the conditions at STP.

9. Why is it only necessary to "memorize" the combined gas law instead of all three separately?

10. Why is it necessary to carry an oxygen tank when climbing Mt Everest?

11. The Titanic is 2 miles under water. What pressure is it under in psi?

12. Why doesn’t water boil at 100°C in Somerset?

13. Can the speed of a given molecule in a gas double at constant temperature?

Would that change the total kinetic energy of the system?

14. How much energy is required to completely vaporize 53.8 g of lead at its boiling point?

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LAB: MOLES

  1. Set up the apparatus as shown in Figure 1.

Figure 1

  1. Wash and dry the crucible. Place the crucible on the pipestem triangle with the lid offset and heat it strongly for 2 minutes. If the bottom of the crucible starts to glow red, reduce the heat.
  1. After the two minutes, turn the burner off, cover the crucible. and set the crucible on the table and allow it to cool.
  1. When cool, mass the crucible and cover.
  1. Obtain a 20 cm piece of magnesium ribbon and, if necessary, clean it with steel wool until it is lustrous.
  1. Roll the magnesium around a pencil until you have a tight coil.
  1. Place the magnesium in the crucible and determine the mass of the crucible, cover, and contents.
  1. Cover the crucible and begin to heat it gently for 2 minutes.
  1. Increase the heat slightly, and heat for an additional 2 minutes.
  1. Using a paper clip and remove the lid of the crucible and heat strongly for 10 minutes.
  1. Discontinue heating. Observe the contents of the crucible. If the contents are still shiny, tell the instructor.
  1. Cover the crucible and allow it to cool to room temperature.
  1. Once cool, use an eyedropper and add just enough water to cover the magnesium oxide in the crucible.
  1. Offset the lid on the crucible and heat it gently until all of the water has evaporated (about 2 minutes).
  1. Uncover the crucible and heat it strongly for 5 minutes.
  1. Cover the crucible and allow it to cool to room temperature.
  1. Determine the mass of the crucible, cover, and magnesium oxide.

Calculations:

1. Mass of crucible and cover.______g

2. Mass of crucible, cover, and magnesium.______g

3. Mass of magnesium.______g

4. Moles of magnesium.______mols

5. Mass of crucible, cover, and magnesium oxide______g

6. Mass of magnesium oxide.______g

7. Mass of combined oxygen.______g

8. Moles of combined oxygen.______mols

9. Mole ratio of magnesium to oxygen______

Lab: Boyle’s Law/20

Procedure:

  1. Assemble the Boyle's Law apparatus. Make sure to remove the cap from the syringe. See Figure 1.
  1. Place the piston inside the syringe to a volume between 30.0 and 35.0 cm3. Place the cap on the end of the syringe.
  1. Measure and record your initial volume.
  1. Add a 500 g mass to the top of the apparatus. Record the new volume for this mass.
  1. Successively place 1000 g, 1500 g and 2000 g on the apparatus and record the volume.
  1. Remove the masses and do a second and third trial.

7. After 3 trials obtain an average.

8. Convert these masses to pressures in N/cm2.

9. Turn in a data table and graph for both pressure (N/cm2) vs average volume and for pressure vs 1/average volume. Graphing must be done using Excel and make sure to include the R2 value. (12 pts)

10. What information is shown by your P vs V graph? (2 pts)

11. By keeping the cap on the syringe, which characteristic of a gas are we keeping constant: P, V, or n? Explain. (2 pts). T is NOT being held constant, explain what effect, if any, this would have on you data. (2 pts)

12. What is the point of doing not only a P vs V graph but also a P vs 1/V graph? (Hint: Look at the shape of the lines or the R2.) (2 pts)

Figure 1

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