Ch.5 - GasesSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Understanding Pressure

Concept #1: Pressure vs. Force 

Concept #2: The different units for Pressure

Although the SI unit for pressure is the Pascal, most professors use atm, mmHg or torrs as the everyday units for pressure. 

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Example #1: A geochemist heats a limestone (CaCO3) sample and collects the CO2 released in an evacuated flask. The CO2 pressure is 283.7 mmHg. Calculate the CO2 pressure in torrs and atmospheres.

The conversion of units of pressure is simply a dimensional analysis question. Recall the dimensional analysis relationships been volume and length.  

Practice: If the barometer in a laboratory reads 34.2 inHg what is the pressure in bars? (1 in = 2.54 cm)

Additional Problems
Which of the following indicates the greatest pressure? a. 1 atm b. 777 torr c. 5.5 mm Hg d. 1000 Pa e. 12 psi
The pressure in Denver. Colorado (elevation 5280 ft). averages about 24.9 in mmHg. Convert this pressure to a. atm
The pressure on top of Mt. Everest averages about 235 mmHg. Convert this pressure to a. torr
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12,1979, in the Western Pacifie Ocean. Convert this pressure to  a. torr
The pressure in Denver. Colorado (elevation 5280 ft). averages about 24.9 in Hg. Convert this pressure to b. mmHg
The pressure in Denver. Colorado (elevation 5280 ft). averages about 24.9 in Hg. Convert this pressure to c. psi
Which of the following is  NOT a unit for pressure? A) Pa         B) mmHg        C) atm             D) torr             E) liter
The pressure in Denver. Colorado (elevation 5280 ft). averages about 24.9 in Hg. Convert this pressure to d. Pa
The pressure on top of Mt. Everest averages about 235 mmHg. Convert this pressure to b. psi
The pressure on top of Mt. Everest averages about 235 mmHg. Convert this pressure to c. in Hg
The pressure on top of Mt. Everest averages about 235 mmHg. Convert this pressure to d. atm
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12,1979, in the Western Pacifie Ocean. Convert this pressure to  b. atm
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12,1979, in the Western Pacifie Ocean. Convert this pressure to  c. in Hg
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12,1979, in the Western Pacifie Ocean. Convert this pressure to  d. psi
Convert a pressure of 753 torr to a pressure inkPa
Convert a pressure of 753 torr to a pressure inbar
The pressure in Denver, Colorado (elevation 5280 ft), averages about 24.9 inHg.Convert this pressure to Pa.
The North American record for highest recorded barometric pressure is 31.85 inHg, set in 1989 in Northway, Alaska.Convert this pressure to kPa (kilopascals).
The typical atmospheric pressure on top of Mt. Everest (29,028 ft) is about 265 torr. Convert this pressure to the following units. You may want to reference (Pages 398 - 400) Section 10.2 while completing this problem.pascals
The typical atmospheric pressure on top of Mt. Everest (29,028 ft) is about 265 torr. Convert this pressure to the following units. You may want to reference (Pages 398 - 400) Section 10.2 while completing this problem.bars
Perform the following conversions of pressure. You may want to reference(Pages 397 - 400)Section 10.2 while completing this problem.0.665 bar to kilopascals
Perform the following conversions of pressure. You may want to reference(Pages 397 - 400)Section 10.2 while completing this problem.2.50 atm to bars
The pressure on top of Mount Everest (29,029 ft) averages about 235 mmHg. You may want to reference (Pages 201 - 201) Section 5.2 while completing this problem.Convert this pressure to psi.
The pressure in Denver, Colorado (elevation 5280 ft), averages about 24.9 inHg.Convert this pressure to psi.
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12, 1979, in the Western Pacific Ocean.Convert this pressure to psi.
The typical atmospheric pressure on top of Mt. Everest (29,028 ft) is about 265 torr. Convert this pressure to the following units. You may want to reference (Pages 398 - 400) Section 10.2 while completing this problem.psi
You may want to reference (Pages 201 - 201) Section 5.2 while completing this problem.Your local weather report announces that the barometric pressure is 29.56 inHg . Convert this pressure to psi.
Convert a pressure of 753 torr to a pressure inatm
The pressure on top of Mount Everest (29,029 ft) averages about 235 mmHg. You may want to reference (Pages 201 - 201) Section 5.2 while completing this problem.Convert this pressure to atm.
The pressure in Denver, Colorado (elevation 5280 ft), averages about 24.9 inHg.Convert this pressure to atm.
The North American record for highest recorded barometric pressure is 31.85 inHg, set in 1989 in Northway, Alaska.Convert this pressure to atm.
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12, 1979, in the Western Pacific Ocean.Convert this pressure to atm.
The typical atmospheric pressure on top of Mt. Everest (29,028 ft) is about 265 torr. Convert this pressure to the following units. You may want to reference (Pages 398 - 400) Section 10.2 while completing this problem.atm
Perform the following conversions of pressure. You may want to reference(Pages 397 - 400)Section 10.2 while completing this problem.660 mmHg to atmospheres
Perform the following conversions of pressure. You may want to reference(Pages 397 - 400)Section 10.2 while completing this problem.1.326×105 Pa to atmospheres
Hurricane Wilma of 2005 is the most intense hurricane on record in the Atlantic basin, with a low-pressure reading of 882 mbar (millibars).Convert this reading into atmospheres.
In the United States, barometric pressures are generally reported in inches of mercury (in. ). On a beautiful summer day in Chicago, the barometric pressure is 30.47 in. Hg .Convert this pressure to atm.
The pressure on top of Mount Everest (29,029 ft) averages about 235 mmHg. You may want to reference (Pages 201 - 201) Section 5.2 while completing this problem.Convert this pressure to torr.
The North American record for highest recorded barometric pressure is 31.85 inHg, set in 1989 in Northway, Alaska.Convert this pressure to torr.
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12, 1979, in the Western Pacific Ocean.Convert this pressure to torr.
Perform the following conversions of pressure. You may want to reference(Pages 397 - 400)Section 10.2 while completing this problem.0.932 atm to torr
Hurricane Wilma of 2005 is the most intense hurricane on record in the Atlantic basin, with a low-pressure reading of 882 mbar (millibars).Convert this reading into torr.
In the United States, barometric pressures are generally reported in inches of mercury (in. ). On a beautiful summer day in Chicago, the barometric pressure is 30.47 in. Hg .Convert this pressure to torr.
Convert a pressure of 753 torr to a pressure inmmHg
The pressure on top of Mount Everest (29,029 ft) averages about 235 mmHg. You may want to reference (Pages 201 - 201) Section 5.2 while completing this problem.Convert this pressure to inHg.
The pressure in Denver, Colorado (elevation 5280 ft), averages about 24.9 inHg.Convert this pressure to mmHg.
The North American record for highest recorded barometric pressure is 31.85 inHg, set in 1989 in Northway, Alaska.Convert this pressure to mmHg.
The world record for lowest pressure (at sea level) was 652.5 mmHg recorded inside Typhoon Tip on October 12, 1979, in the Western Pacific Ocean.Convert this pressure to inHg.
The typical atmospheric pressure on top of Mt. Everest (29,028 ft) is about 265 torr. Convert this pressure to the following units. You may want to reference (Pages 398 - 400) Section 10.2 while completing this problem.mmHg
Hurricane Wilma of 2005 is the most intense hurricane on record in the Atlantic basin, with a low-pressure reading of 882 mbar (millibars).Convert this reading into inches of Hg.
Which units are appropriate for expressing atmospheric pressures?
What is pressure?
What causes pressure?
Rank the common units of pressure in order of smallest to largest unit.
Consider a planet where the pressure of the atmosphere at sea level is 2500 mmHg. Will water behave in a way that can sustain life on this planet?
What are some common units of pressure?
Suppose that a woman weighing 140 lbs and wearing high-heeled shoes momentarily places all her weight on the heel of one foot. You may want to reference (Pages 413 - 415) Section 10.2 while completing this problem.If the area of the heel is 0.55 in2, calculate the pressure exerted on the underlying surface in pounds per square inch.
Suppose that a woman weighing 140 lbs and wearing high-heeled shoes momentarily places all her weight on the heel of one foot. You may want to reference (Pages 413 - 415) Section 10.2 while completing this problem.If the area of the heel is 0.55 in2, calculate the pressure exerted on the underlying surface in kilopascals.
Suppose that a woman weighing 140 lbs and wearing high-heeled shoes momentarily places all her weight on the heel of one foot. You may want to reference (Pages 413 - 415) Section 10.2 while completing this problem.If the area of the heel is 0.55 in2, calculate the pressure exerted on the underlying surface in atmospheres.
An ordinary gasoline can measuring 30.0 cm by 25.0 cm by 20.0 cm is evacuated with a vacuum pump.Assuming that virtually all of the air can be removed from inside the can, and that atmospheric pressure is 14.7 psi, what is the total force (in pounds) on the surface of the can?
Mars has an average atmospheric pressure of 0.007 atm.Would it be easier or harder to drink from a straw on Mars than on Earth?
Convert 1.50 atm to torr. A) 760 torr B) 875 torr C) 1140 torr D) 1000 torr E) 1520 torr
The pressure on top of Mt. Everest averages about 235 mmHg.1.) Convert this pressure to torr.2.) Convert this pressure to psi.3.) Convert this pressure to inHg.4.) Convert this pressure to atm.
Convert 1.50 atm to torr. A) 760 torr B) 875 torr C) 1140 torr D) 1000 torr E) 1520 torr
The atmospheric pressure is 700 mm Hg. What is the pressure in inches of Hg?A) 16.0 in HgB) 0.921 in HgC) 13.5 in HgD) 27.6 in HgE) 32.5 in Hg
A sample of N2O gas has a density of 2.85 g/L at 298 K. What is the pressure of the gas (in mmHg)? 
Freon-12 (CF2Cl2) is commonly used as the refrigerant in central home air conditioners. The system is initially charged to a pressure of 4.8 atm. Express this pressure in each of the following units (1 atm = 14.7 psi).c. Pa
A gauge on a compressed gas cylinder reads 2200 psi (pounds per square inch; 1 atm = 14.7 psi). Express this pressure in each of the following units.b. megapascals (MPa)
Canadian tire pressure gauges are marked in units of kilopascals. What reading on such a gauge corresponds to 32 psi?
Consider this scenario and answer the following questions: On a mid-August day in the northeastern United States, the following information appeared in the local newspaper: atmospheric pressure at sea level 29.97 in. Hg, 1013.9 mbar.(a) What was the pressure in kPa?
You may want to reference (Pages 201 - 201) Section 5.2 while completing this problem.Convert a pressure of 23.2 inHg to kilopascals.
Convert the following:(b) 992 torr to bar
Convert the following:(d) 804 mmHg to kPa
Convert the following:(b) 27.5 atm to kPa
Convert the following:(c) 6.50 atm to bar 
Convert each of the pressures described below to atm:(c) The surface of Venus has an atmospheric pressure of 9.15×10 6 Pa.
Freon-12 (CF2Cl2) is commonly used as the refrigerant in central home air conditioners. The system is initially charged to a pressure of 4.8 atm. Express this pressure in each of the following units (1 atm = 14.7 psi).d. psi
The pressure of the atmosphere on the surface of the planet Venus is about 88.8 atm. Compare that pressure in psi to the normal pressure on earth at sea level in psi
Convert each of the pressures described below to atm:(b) A cyclist fills her bike tires to 86 psi.
A gauge on a compressed gas cylinder reads 2200 psi (pounds per square inch; 1 atm = 14.7 psi). Express this pressure in each of the following units.a. standard atmospheres
Convert the following:(a) 0.745 atm to mmHg 
Convert the following:(c) 365 kPa to atm 
Convert the following:(a) 76.8 cmHg to atm 
Convert each of the pressures described below to atm:(a) At the peak of Mt. Everest, atmospheric pressure is only 2.75×10 2 mmHg.
Freon-12 (CF2Cl2) is commonly used as the refrigerant in central home air conditioners. The system is initially charged to a pressure of 4.8 atm. Express this pressure in each of the following units (1 atm = 14.7 psi).b. torr
A gauge on a compressed gas cylinder reads 2200 psi (pounds per square inch; 1 atm = 14.7 psi). Express this pressure in each of the following units.c. torr
Consider this scenario and answer the following questions: On a mid-August day in the northeastern United States, the following information appeared in the local newspaper: atmospheric pressure at sea level 29.97 in. Hg, 1013.9 mbar.(b) The pressure near the seacoast in the northeastern United States is usually reported near 30.0 in. Hg. During a hurricane, the pressure may fall to near 28.0 in. Hg. Calculate the drop in pressure in torr
Convert the following:(d) 0.937 kPa to torr
Convert each of the pressures described below to atm:(d) At 100 ft below sea level, a scuba diver experiences a pressure of 2.54×10 4 torr.
Freon-12 (CF2Cl2) is commonly used as the refrigerant in central home air conditioners. The system is initially charged to a pressure of 4.8 atm. Express this pressure in each of the following units (1 atm = 14.7 psi).a. mm Hg
An “empty” gasoline can with dimensions 15.0 cm by 40.0 cm by 12.5 cm is attached to a vacuum pump and evacuated. If the atmospheric pressure is 14.7 lb/in2, what is the total force (in pounds) on the outside of the can?
Why are sharp knives more effective than dull knives (Hint: think about the definition of pressure)?
Why do some small bridges have weight limits that depend on how many wheels or axles the crossing vehicle has?
Why should you roll or belly-crawl rather than walk across a thinly-frozen pond?
The gravitational force exerted by an object is given by F = mg, where F is the force in newtons, m is the mass in kilograms, and g is the acceleration due to gravity (9.81 m/s 2). (a) Use the definition of the pascal to calculate the mass (in kg) of the atmosphere above 1 m  2 of ocean.
A typical barometric pressure in Redding, California, is about 750 mm Hg. Calculate this pressure in atm and kPa
A typical barometric pressure in Denver, Colorado, is 615 mm Hg. What is this pressure in atmospheres and kilopascals?
A typical barometric pressure in Kansas City is 740 torr. What is this pressure in atmospheres, in millimeters of mercury, and in kilopascals?
During the Viking landings on Mars, the atmospheric pressure was determined to be on the average about 6.50 millibars (1 bar = 0.987 atm). What is that pressure in torr and kPa?
A medical laboratory catalog describes the pressure in a cylinder of a gas as 14.82 MPa. What is the pressure of this gas in atmospheres and torr?
An oxygen tank contains oxygen (O2) at a pressure of 9 50 atm. Part AWhat is the pressure in the tank in torr? Part BWhat is the pressure in the tank in mmHg?
The pressure 70.0 meters under water is 788 kPa.What is this pressure in atm?What is this pressure in mmHg? 
High-pressure liquid chromatography (HPLC) is a method used in chemistry and biochemistry to purify chemical substances. The pressures used in this procedure range from around 500 kilopascals (500,000 Pa) to about 60,000 kPa (60,000,000 Pa). It is often convenient to know the pressure in torr. If an HPLC procedure is running at a pressure of 2.90 x 108 Pa, what is its running pressure in torr? Express the pressure numerically in torr.
The atmospheric pressure in New York City on a certain day was 768 mm Hg. What was the pressure in kPa?a. 1.02 x 105 kPa b. 584 kPa c. 5.76 x 10-3 kPa d. 102 kPa e. none of the above
The pressure in car tires is often measured in pounds per square inch (lb/in.2), with the recommended pressure being in the range of 25 to 45 lb/in.2. Suppose a tire has a pressure of 37.5 lb/in.2. Convert 37.5 lb/in.2 to its equivalent in atmospheres. Express the pressure numerically in atmospheres.
The pressure 70.0 meters under water is 788 kPa. What is this pressure in bar? What is this pressure in torr?
On a climb up Mt. Whitney, the atmospheric pressure is 531 mmHg.Part A  What is the pressure in atm? Part B What is the pressure in torr? 
An airplane cabin is pressurized to 620 mmHg. What is the pressure inside the cabin in atmospheres?
The atmospheric pressure on the surface of Venus is 9120. kPa. Calculate the atmospheric pressure in atm. Be sure your answer has the right number of significant digits.
The density of mercury is 13.5 g/mL and the density of water is 1.00 g/mL. lf a mercury barometer reads 727 mmHg, what is the barometric pressure in cm H 2O?
An ordinary gasoline can measuring 30.0 cm by 15.0 cm by 10.0 cm is evacuated with a vacuum pump. Assuming that virtually all of the air can be removed from inside the can, and that atmospheric pressure is 14.7 psi, what is the total force (in pounds) on the surface of the can?