UNIT: Gas Laws
Test Improvement
Directions:
· You must complete the questions for the learning targets that you did not get completely correct on the unit test. Print those questions and complete them. They must be completed and checked before you take the new test.
· Websites with tutorials and extra problems have been listed for additional help. Please use them if you need further practice or further explanation.
· Optional: you can complete all of the learning target questions for additional practice.
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LT1: Describe the general properties of gases.
Questions:
1. In your own words, explain how the following properties pertain to gases:
- Compressibility
- Diffusion
- Effusion
- Expansion
- Fluidity
- Pressure
LT2: Explain the components of the kinetic molecular theory.
Questions:
1. In your own words, list the parts of the kinetic molecular theory.
2. Which component of the KMT supports each of the following? Also explain how that part of the KMT fits the example.:
a. Gas molecules of different types do not stick together when near each other.
b. A container with a gas in it was opened. The gas left the container.
c. Gas molecules at 25 degrees celsius move slower than gas molecules at 37 degrees celsius.
d. A balloon can be squeezed without popping it.
3. What is the difference between an ideal gas and a real gas?
LT3: Describe how a mercury barometer is used to measure pressure.
Questions:
1. Sketch a barometer. Label the parts. Explain how it is used to measure atmospheric pressure.
LT4: Describe what pressure is.
Questions:
1. Sally stepped on your foot with high heels. The next day Sally stepped on your foot with flat shoes. Which time would hurt more? Explain why in terms of pressure. Do NOT just say the pressure is greater with one of the shoes….explain why it is greater.
LT5: Convert between units of pressure.
Questions:
1. Convert each of the following:
a. 826 torr à atm
b. 3.5 kPa à atm
c. 925 torr à mm Hg
d. 4.25 atm à mm Hg
e. 875 mm Hg à atm
LT5: Explain what temperature measures.
Questions:
1. In your own words, explain this LT.
LT6: Convert between units of temperature.
Questions:
1. Convert each of the following:
a. 325 K à ۫C
b. 45.2 ۫ F à ۫C
c. 55۫C à K
d. 85.5 ۫ F à K
LT 7 Explain the relationships in Boyle’s Law.
Questions:
1. What variables remain constant in Boyle’s Law?
2. What variables change in Boyle’s Law?
3. Is the relationship between the changing variables directly proportional or inversely proportional? Explain.
LT 8 Solve for unknown variables using Boyle’s Law.
Questions:
1. What units do the different variables have to be in for Boyle’s Law?
2. A sample of neon gas occupies a volume of 2.8L at 1.8 atm. What will its volume be at 1.2 atm?
3. To what pressure would you have to compress 48.0 L of oxygen gas at 99.3 kPa in order to reduce its volume to 16,000 mL?
4. A chemist collects 59.0 mL of sulfur dioxide gas on a day when the atmospheric pressure is 0.989 atm. On the next day, the pressure has changed to 735 mmHg. What will be the volume of the gas on the second day?
LT 9 Explain the relationships in Charles’ Law.
Questions:
1. What variables remain constant in Charles’ Law?
2. What variables change in Charles’ Law?
3. Is the relationship between the changing variables directly proportional or inversely proportional? Explain.
LT10 Solve for unknown variables using Charles’ Law.
Questions:
1. What units do the different variables have to be in for Charles’ Law?
2. A balloon full of air has a volume of 2.75L at a temperature of 18۫C. What is the balloon’s volume at 45۫C?
3. A sample of argon has a volume of 0.43 mL at 24۫C. At what temperature in degrees Celsius will it have a volume of 0.57 mL?
4. 40.0 mL of a gas at 280. K is heated to a temperature of 77۫C. What is the new volume in mL?
LT11 Explain the relationships in the Combined Gas Law.
Questions:
1. What variables remain constant in the Combined Gas Law?
2. What variables change in the Combined Gas Law?
LT 12 Solve for unknown variables in the Combined Gas Law.
Questions:
1. What units do the different variables have to be in for the Combined Gas Law?
2. A sample of hydrogen gas has a volume of 65.0 mL at a pressure of 0.992 atm and a temperature of 16۫C. What volume (in mL) will the hydrogen occupy at 748 mmHg and 25۫C?
3. A student collects 450. mL of hydrogen chloride gas at a pressure of 100. kPa and a tempearture of 17۫C. What is the volume (in mL) of the HCl at 273 KI and 765 mmHg?
LT13 Explain the relationships in Avogadro’s Law.
Questions:
1. What variables remain constant in Avogadro’s Law?
2. What variables change in Avogadro’s Law?
3. Is the relationship between the changing variables directly proportional or inversely proportional? Explain.
LT 14 Solve for unknown variables in Avogadro’s Law.
Questions:
1. 2.5 mols of helium gas occupies 0.375 L. How many mols of the helium will occupy ten times that volume?
2. 0.125 mols of gas occupy 275 mL. How many L of that gas will 1.00 mols occupy?
LT 15 Solve Ideal Gas Law problems using moles.
Questions:
1. An engineer pumps 5.00 mol of carbon monoxide gas into a cylinder that has a capacity of 20.0L. What is the pressure in kPa of CO inside the cylinder at 25۫C?
2. A student collects 425 mL of oxygen at a temperature of 24۫C and a pressure of 0.899 atm. How many moles of oxygen did the student collect?
LT 16 Solve Ideal Gas Law problems using grams.
Questions:
1. What volume (in L) will 8.47 kg of sulfur dioxide gas occupy at a pressure of 89.4 kPa and a temperature of 40.۫C?
2. A tank with a volume of 658 mL contains 1.50 g of neon gas. The maximum safe pressure that the tank can withstand is 4.50 x 102 kPa. At what temperature (in ۫C) will the tank have that pressure?
LT 17 Solve problems using Dalton’s Law of Partial Pressure.
LT 20 Solve gas problems over H2O or Hg.
Questions:
1. A chemist collects a sample of gas over water at a temperature of 27۫C. The total pressure of the gas that has displaced a volume of 15 mL of water is 207.33 kPa. What is the pressure of the gas collected? (in kPa)
2. Seinfeld did a chemical reaction where the gas was collected over water. The total pressure involved was 825 mmHg. What is the pressure of the gas if the temperature he did this at was 24.5 ۫C?
LT 18 Solve gas stoichiometry problems.
Questions:
1. Dinitrogen pentoxide decomposes into nitrogen dioxide and oxygen. If 5.00L of N2O5 reacts at STP, what volume of nitrogen dioxide is produced when measured at 64.5۫C and 1.76 atm?
2. Carbon monoxide will burn in air (with oxygen gas) to produce carbon dioxide. What volume of oxygen will be needed to react with 3.50 g CO at 20.0۫C and a pressure of 0.953 atm?
LT 19 Relate distance a gas travels to its molar mass using Graham's law.
Questions:
1. Explain the relationship between molar mass and velocity of the gas molecules.
2. Which will move faster…..chlorine gas or helium gas?
3. Which will move faster… iodine gas or fluorine gas?
LT 21 Calculate molar volume of a gas.
Questions:
1. What is the volume of 2.50 mols of helium at STP?
2. How many mols of chlorine gas occupy 1250 mL at STP?