MORE… Mole/Gas Laws Review

__Vocabulary__

gas |
pressure |
volume |
temperature |

Kelvin |
kinetic energy |
partial pressure |
mm Hg |

atm |
Boyle's Law |
Charle's Law |
Gay-Lussac's Law |

Ideal Gas Law |
ideal gas constant |
diffusion |
Graham's Law |

__ __

__Important
Identities__

K = °C + 273 and 1 atm = ______mmHg

Dalton's Law of Partial Pressure:

Boyle's
Law for P-V Changes [___________ Proportion]:_{}

Charle's Law for T-V Changes [_________ Proportion]:

Combined Gas Law:

Ideal Gas Law:

where R =
__________

n = _____________

Review Problems

1. Explain whether the two variables in each scenario are directly or inversely related.

(a) What happens to the pressure when gas particles
are added or removed at a constant volume and constant temperature?

(b) What happens to the pressure when the volume is
either increased or decreased at a constant temperature and constant number of
gas particles?

2. Dalton’s Law of Partial Pressure: A gas mixture
containing oxygen, nitrogen, and carbon dioxide has a total pressure of 250 mm
Hg. If P= 50 mm Hg, P= 175 mm Hg, what is P? What is the
total pressure in atm?

3. Boyle's Law for Pressure-Volume Changes:

(a) The
pressure on 2.50 L of anesthetic gas is changed from 760 mm Hg to 304 mm
Hg. What will be the new volume if the
temperature remains constant?

(b) A given mass of air has a volume of 6.0 L at 1 atm. What volume will it occupy at 190 mm Hg if the temperature does not change?

4. Charle's Law for Temperature-Volume Changes:

(a) If a sample of gas occupies 6.8 L at 327 °C, what
is the volume at 27 °C if the pressure does not change?

(b) Five liters of air at -50 °C are warmed to 100
°C. What is the new volume if the
pressure is constant?

5. Combined
Gas Law:
A 5.0 L air sample at a temperature of -50 °C has a pressure of 800 mm
Hg. What will be the new pressure if
the temperature is raised to 100 °C and the volume expands to 7.0 L?

6.
Ideal Gas Law: What pressure will be exerted by 0.450 mol of a gas at 25 °C if it
is contained in a vessel whose volume is 650 cm^{3 }(1 cm^{3 }= 1mL)?

** **

Mastery Problems

7. If 4.50 gm of methane gas (CH_{4}) is
introduced into an evacuated 2.00 L container at

35
°C, what is the pressure in the container in atm?

8. A 3.50 L gas sample at 20 °C and a pressure of 650
mm Hg is allow to expand to a volume of 8.00 L. the final pressure of the gas is 425 mm Hg. What is the final temperature of the gas in
degrees Celsius?

9. A gas cylinder contains nitrogen gas at 10 atm
pressure and a temperature of 20 °C.
The cylinder is left in the sun, and the temperature of the gas
increases to 50 °C. What is the pressure
in the cylinder?

10. Calculate the number of liters occupied at STP for
a & b:

(a) 2.5 mol N_{2} (b) 0.600 gm H_{2}

11. 2 KClO_{3} ®
2 KCl + 3 O_{2}

How many grams of potassium chloride are
produced if 25.0 g of potassium chlorate decompose?

12. N_{2}
+ 3 H_{2} ® 2 NH_{3}

How many grams of hydrogen are necessary
to react completely with 50.0 g of nitrogen in the above reaction?

13. Calculate the percent of each element present in potassium phosphate from its formula.