Gas Laws Review AP Chemistry

The density of an unknown gas is 2.00 grams per Liter at 3.00 atmosphere pressure and 127^oC. What is the molar mass of this gas?

• (254/3) R

• 188 R

• (800/3) R

• 600 R

A gaseous mixture containing 7.0 moles of nitrogen, 2.5 moles of oxygen, and 0.5 moles of helium exerts a total pressure of 0.90 atmosphere. What is the partial pressure of the nitrogen?

• 0.13 atm

• 0.27 atm

• 0.63 atm

• 0.90 atm

A 2.00-liter sample of nitrogen gas at 27° C and 600. millimeters of mercury is heated until it occupies a volume of 5.00 liters. If the pressure remains unchanged, the final temperature of the gas is

• 68^o C

• 120^o C

• 477^o C

• 677^o C

A sample of 0.010 mole of oxygen gas is confined at 127°C and 0.80 atmosphere. What would be the pressure of this sample at 27°C and the same volume?

• 0.10 atm

• 0.20 atm

• 0.60 atm

• 0.80 atm

A sample of 3.0 grams of an ideal gas at 127°C and 1.0 atmosphere pressure has a volume of 1.5 liters. Which of the following expressions is correct for the molar mass of the gas? The ideal gas constant, R, is 0.08 (L ⋅ atm)/(mole ⋅ K).

• [(0.08)(400)] /[(3.0)(1.0)(1.5)]

• [(1.0)(1.5)]/ [(3.0)(0.08)(400)]

• [(0.08)(1.0)(1.5)] /[(3.0)(400)]

• [(3.0)(0.08)(400)] /[(1.0)(1.5)]

The system shown above is at equilibrium at 28 °C. At this temperature, the vapor pressure of water is 28 millimeters of mercury. The partial pressure of O2(g) in the system is

• 28 mm Hg

• 56 mm Hg

• 133 mm Hg

• 161 mm Hg

NH₄NO₃(s) → N₂O(g) + 2 H₂O(g)

A 0.03 mol sample of NH₄NO₃(s) is placed in a 1 L evacuated flask, which is then sealed and heated. The NH₄NO₃(s) decomposes completely according to the balanced equation above. The total pressure in the flask measured at 400 K is closest to which of the following? ( The value of the gas constant, R, is 0.082 L atm mol^–1 K^–1)

• 3 atm

• 1 atm

• 0.5 atm

• 0.1 atm

A flask contains 0.25 mole of SO₂(g), 0.50 mole of CH₄(g), and 0.50 mole of O₂(g). The total pressure of the gases in the flask is 800 mm Hg. What is the partial pressure of the SO₂(g) in the flask?

• 600 mm Hg

• 250 mm Hg

• 200 mm Hg

• 160 mm Hg

A hydrocarbon gas with an empirical formula CH2 has a density of 1.88 grams per liter at 0°C and 1.00 atmosphere. A possible formula for the hydrocarbon is

• CH₂

• C₂H₄

• C₃H₆

• C₄H₈

Hydrogen gas is collected over water at 24° C. The total pressure of the sample is 755 millimeters of mercury. At 24° C, the vapor pressure of water is 22 millimeters of mercury. What is the partial pressure of the hydrogen gas?

• 22 mm Hg

• 733 mm Hg

• 755 mm Hg

• 760 mm Hg