Lesson 5.3 Ideal Gas Law Calculations Supplemental PV = nRT

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Lesson 5.3 Ideal Gas Law Calculations Supplemental

1.

2.

3.

4.

5.

6.

7.

8.

9.

A.

PV = nRT Poster Problems: Complete the “you do” problems in your packet.

1. Calculate the temperature in ℃ of 0.500

moles of nitrogen gas occupying a 15.0 L

rigid tank at a pressure of 650. mmHg.

2. How many moles of helium gas are trapped

in a 25.0 L balloon when the gas has a

pressure of 102 kPa and a temperature of

9.00

?

3. What is the mass of oxygen gas in a 80.0 L

balloon at room temperature, 20.0

℃ , and a

10.

pressure of 99.3 kPa?

4. Calculate the pressure in atm of 10.0 g of

propane gas in a cylinder with a volume of 50.0 L

and a temperature of 35.0

. (Propane is C

3

H

8

.)

5. An oxygen sample has 2.50 g of gas at a pressure

of 0.900 atm and is held at 19.0

℃ . What is the

volume of the sample?

6. What is the volume of 1.00 g of butane gas at

STP? (Butane is C

4

H

10

.)

B.

PV = nRT Problems involving Molar Mass and Density

Because the ideal gas involves variables of moles and volume, you can rearrange the equation to solve for molar mass (remember: that’s mass divided by # of moles) or for density (remember: that’s mass divided by volume). Here’s the proof:

Density = Molar mass =

Practice Problems

7. Calculate the density a gas will have at STP if its molar mass is 28.7 g/mol. (1.28 g/L)

8. Uranium hexafluoride, UF

4

, is a solid at room temperature, but it boils at 56 o

C. Determine the density of uranium hexafluoride at 60 o

C and 745 mmHg. (11.3 g/L)

9. Calculate the molar mass of a gas if 35.44 g of the gas stored in a 7.50 L tank exerts a pressure of

60.0 atm at a constant temperature of 35.5 °C. (1.99 g/mol)

10. What is the molar mass of a gas if 273 mL of the gas weighs 0.80 grams at 27 o

C and 380 torr?

(144. g/mol)

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