Behavior of Gases--Schedule and Homework

(11 Days)


Date

Topic(s)

Reading

Homework

10/24

  • The Kinetic Theory Applied to Gases
  • Temperature, pp 74 - 75
  • Kinetic Theory, Gas Pressure, and Kinetic Energy and Kelvin Temperature, pp 267 - 272
  • Section Review: 30 - 35 p 75
  • Concept Practice: 22 - 28, p 289

10/25

  • Factors Affecting Gas Pressure
  • Kinetic Theory Revisited, Variables that Describe a Gas, Amount of Gas, Volume, Temperature, pp 327 - 331
  • Section Review: 1 - 4, p 328
  • Section Review: 5 - 9, p 332

10/26 

  • OSU College of Forestry Presentation
  • Pressure-Volume Relationship: Boyle's Law Simulation
  • Pressure-Volume Relationship: Boyle's Law, pp 333 - 334
  • Write-Up: Pressure-Volume Relationship
  • Concept Practice: 46, 48, p 356

10/29 

  • Temperature-Volume Relationship
  • Charles's Law
  • Absolute Zero
  • Temperature-Volume Relationship: Charles's Law and Temperature-Pressure Relationship: Gay-Lussac's Law, pp 335- 338
  • Supplemental Problems: 1 - 6

10/30

  • Pressure-Temperature Relationship: Gay-Lussac's Law Simulation
  • The Combined Gas Law , pp 339 - 340
  • Write-Up: Pressure-Temperature Relationship
  • Concept Practice: 51 - 56, p 356

10/31

  • The Combined Gas Law
  • Standard Temperature and Pressure
  • Gas Stoichiometry
  • Avogadro's Hypothesis, Dalton's Law, Graham's Law pp 347 - 353
  • Supplemental Problems: 7 - 14

11/5

  • Gas Stoichiometry Problems
  • Dalton's Law of Partial Pressures
  
  • Pre-Lab Molar Volume of H2 Gas

11/6

  • Molar Volume of H2 Gas
 
  • Write-Up Molar Volume of H2 Gas

11/7

  • Molecular Velocities
  • More Gas Stoichiometry, Partial Pressure, and Molecular Velocity Problems
  • Avogadro's Hypothesis, Dalton's Law, Graham's Law pp 347 - 353
  • Concept Practice 62 - 64, 66 p 356 (62 is hard!)
  • Supplemental Problems: 15 - 17

11/8

  • Unit 4 Test Review
  • Chapter 12 Study Guide (Neglect Section 12.4)
  • Study!!

11/9

  • Unit 4 Test
  •  Chapter 12 Study Guide (Neglect Section 12.4)
  •  Pre-Lab: Specific Heat

 

Labs: Boyle's Law, Pressure-Temperature Relationship, Molar Volume of H2

Supplemental Problems:
 

Use Boyle's Law (P1V1 = P2V2) to answer the following questions 1 - 3:

   
1. 4.00 g of helium gas at 1.00 atm and 0 oC occupy a volume of 22.4 liters. What would the volume be at 1.75 atm and 0 oC?
   
2. A two-liter vessel contains gas at 81 KPa. If the volume of the vessel were decreased by 400 mL, what would be the new pressure?
   
3. A 2.50-liter sample of dry air in a cylinder exerts a pressure of 3.00 atmospheres at 25 oC. Without change in temperature, a piston is moved until the pressure in the cylinder is reduced to 1.00 atmosphere. What is the volume of the gas?
   
 

The Celsius temperature scale (oC) assigns a value of "0" to the freezing point of water and "100" to the boiling point of water. The Kelvin scale (K) is similar, except it defines "0" to be -273 oC. Convert between the two temperature systems by using the following:

oC = K - 273 or K = oC + 273

4. Convert the following from oC to K:

a) The melting point of water 0 oC c) The melting point of helium -272.2 oC
b) The boiling point of water 100 oC d) the boiling point of helium -268.9 oC
  Convert the following from K to oC:
e) the melting point of copper 1356 K f) the melting point of aspirin 308 K
   
5.

In Figure12.11 on page 335 of your text:

a) What is the relationship between volume and temperature?

b) What seems to happen to the volume of a gas as the temperature approaches -273 oC (or 0 K)?

   
 

The relationship between volume and temperature is known as Charles's Law. When using Charles's Law it is important that you convert all temperatures to Kelvin. Volume is proportional to temperature when they are measured in Kelvin and Kelvin temperatures avoid negative numbers.

V1 / T1 = V2 / T2

6.

Predict the effect of changing the temperatures on the gas samples given below:

a) 2.97 m3 at 72 oC to 144 oC

b) 1 L at 298 K to 0 oC

   
7. If 1.00 x 102 mL of a gas at 10 oC are heated to 20 oC, what will be the approximate volume of the gas? (Pressure and # of molecules are kept constant.)
   
 

A more useful mathematical expression for working with gases combines Boyle's and Charles's Law. (Remember Temps must be in Kelvins!)

V1P1 / T1 = V2P2 / T2

   
8. Freon-12 (CCl2F2) is a chlorofluorocarbon used as a refrigerant that has been implicated in depleting the ozone layer. A typical refrigerator contains 1.25 L of gaseous freon-12 at a pressure of 5.00 KPa and a temperature of -2.00 oC. Calculate the volume the gas would occupy at atmospheric pressure (101.3 KPa) and room temperature (25.00 oC).
   
9.

At 0 oC and 760 mm Hg pressure, one mole of a gas is 22.4 L. Typical surface conditions on Earth and Mars are shown at right. What volume would one mole of a gas occupy on the surface of both planets?

Earth: Temp = 23 oC Press = 760 mm Hg

Mars: Temp = -23 oC Press = 4.0 mm Hg

   
10.

Compressed oxygen gas is sold at a pressure of 130 atmospheres in steel cylinders of 40 liters volume. (Assume 25 oC.) Hint--find what the volume would be at STP.

a) How many moles of oxygen are in one of these cylinders?

b) How many kilograms of oxygen are in one of these cylinders?

   
11.

At STP 1 mole of any gas = 22.4 L. Use this relationship to solve the stoichiometry (mole highway) problem below:

Baking soda, NaHCO3, reacts with vinegar according to the balance reaction shown below. 15.0 g of baking soda would produce how many liters of carbon dioxide gas at STP?

CH3COOH + NaHCO3 H2O + CO2 + CH3COONa

   
12. Sulfur (S8) reacts with oxygen gas to produce sulfur dioxide gas. 50.0 g of S8 would require how many liters of oxygen to react completely at STP?
   
13.

A reaction that produces iron from iron ore is:

Fe2O3 + CO gives Fe + CO2

a) How many grams of CO are needed to produce 1.0 x 103 grams of Fe?

b) How many liters of CO (at STP) are needed to produce 1.0 x 10 3 grams of Fe?

   
14. In the reaction NH3 + O2 gives NO + H2O, how many liters of oxygen are required to react with 4.48 liters of ammonia? All gases are measured at STP.
   
15.

A vessel contains equal numbers of oxygen and hydrogen molecules. The pressure is 760 mm Hg when the volume is 50 liters. Which of these statements is FALSE?

a) On the average, the hydrogen molecules are traveling faster than the oxygen molecules.

b) On the average, more hydrogen molecules strike the walls per second than oxygen molecules.

c) If the oxygen were removed from the system the pressure would drop to 190 mm Hg.

d) Equal numbers of moles of each gas are present.

e) The average kinetic energies of oxygen and hydrogen molecules are the same.

   
16.

Use the stoichiometric relationships ("mole highway") in the above reaction to answer the following:

2 NH3 (g) N2 (g) + 3 H2 (g)

a) 6.0 L of NH3 at STP could produce how many L of N2 at STP?

b) 6.0 L of NH3 at STP could produce how many moles of N2?

c) 6.0 L of NH3 at STP could produce how many grams of N2?

d) 6.0 L of NH3 at STP could produce how many molecules of N2?

e) 6.0 L of NH3 at 2 atm and 25 oC could produce how many grams of N2?

   
17.

In the lab experiment, Reaction of Magnesium with Hydrochloric Acid, the following unbalanced reaction occurred:

Mg (s) + HCl (aq) H2 (g) + MgCl2 (aq)

Magnesium metal was reacted with hydrochloric acid to produce H2 gas, which was collected by displacing water. The atmospheric pressure of the laboratory was 765 mm Hg and room temperature is 20 oC . The vapor pressure of water at 20 oC is 17 mm Hg. Use this information to answer the questions below:

a) Balance the reaction.

b) 0.25 g of Mg would produce how many liters of H2 (g) at STP?

c)Use the atmospheric pressure and the vapor pressure of water to calculate the pressure of H2 (g).

d) Use the combined gas law and your answer to c) to find the volume of H2 under these non-standard conditions.

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