A ballerina weighs 103 lbs and is up on her toes with only 10.0 cm2 of her slippers in contact with the floor. What pressure is she exerting on the floor?

A) 4.59 × 105 Pa B) 4.59 × 103 Pa C) 4.59 × 101 Pa D) 4.59 × 10-1 Pa E) 4.59 × 10-3 Pa A) 4.59 × 105 Pa B) 4.59 × 103 Pa C) 4.59 × 101 Pa D) 4.59 × 10-1 Pa E) 4.59 × 10-3 Pa

A 250.0-mL sample of ammonia, NH3(g), exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container?

A) 0.0787 g B) 0.180 g C) 8.04 g D) 17.0 g E) 59.8 g A) 0.0787 g B) 0.180 g C) 8.04 g D) 17.0 g E) 59.8 g

At moderate pressures (~ 200 atm), the measured pressure exerted by CO2 gas is less than that predicted by the ideal gas equation. This is mainly because

A) such high pressures cannot be accurately measured. B) CO2 will condense to a liquid at 200 atm pressure. C) gas phase collisions prevent CO2 molecules from colliding with the walls of the container. D) of attractive intermolecular forces between CO2 molecules. E) the volume occupied by the CO2 molecules themselves becomes significant. A) such high pressures cannot be accurately measured. B) CO2 will condense to a liquid at 200 atm pressure. C) gas phase collisions prevent CO2 molecules from colliding with the walls of the container. D) of attractive intermolecular forces between CO2 molecules. E) the volume occupied by the CO2 molecules themselves becomes significant.

Exam 5: Gases and the Kinetic-Molecular Theory

At very high pressures (~ 1000 atm), the measured pressure exerted by real gases is greater than that predicted by the ideal gas equation. This is mainly because

(Multiple Choice)

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Question 21

According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average speed.

(True/False)

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Question 22

Ima Chemist found the density of Freon-11 (CFCl₃) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the unknown?

(Multiple Choice)

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Question 23

A sample of an ideal gas has its volume doubled while its temperature remains constant. If the original pressure was 100 torr, what is the new pressure?

(Multiple Choice)

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Question 24

The rate of diffusion of a gas is inversely proportional to its molar mass.

(True/False)

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Question 25

A sample container of carbon monoxide occupies a volume of 435 mL at a pressure of 785 torr and a temperature of 298 K. What would its temperature be if the volume were changed to 265 mL at a pressure of 785 torr?

(Multiple Choice)

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Question 26

For a gas obeying Charles's Law, a plot of V versus 1/T will give a straight line passing through the origin.

(True/False)

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Question 27

"The pressure of an ideal gas is directly proportional to its absolute temperature at constant volume and number of moles" is a statement of ________________ Law.

(Multiple Choice)

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Question 28

A flask containing neon gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where the prevailing pressure is 745 torr. The mercury level in the open arm is 50. mm below that in the arm connected to the flask of neon. What is the neon pressure, in torr?

(Multiple Choice)

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Question 29

The most probable speed of an oxygen molecule in the gas phase at room temperature is 450 m/s. The root-mean-square speed (u_rms) is therefore

(Multiple Choice)

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Question 30

According to the postulates of kinetic-molecular theory, the average kinetic energy of gas molecules is proportional to the absolute temperature.

(True/False)

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Question 31

A ballerina weighs 103 lbs and is up on her toes with only 10.0 cm² of her slippers in contact with the floor. What pressure is she exerting on the floor?

(Multiple Choice)

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Question 32

Assuming ideal behavior, what is the density of argon gas at STP, in g/L?

(Multiple Choice)

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Question 33

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of _____________ Law.

(Multiple Choice)

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Question 34

A 250.0-mL sample of ammonia, NH₃(g), exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container?

(Multiple Choice)

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Question 35

What are the conditions of STP?

(Multiple Choice)

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Question 36

An unknown liquid is vaporized in a 273-mL flask by immersion in a water bath at 99°C. The barometric pressure is 753 torr. If the mass of the vapor retained in the flask is 1.362 g, what is its molar mass?

(Multiple Choice)

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Question 37

At moderate pressures (~ 200 atm), the measured pressure exerted by CO₂ gas is less than that predicted by the ideal gas equation. This is mainly because

(Multiple Choice)

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Question 38

Mineral oil can be used in place of mercury in manometers when small pressure changes are to be measured. What is the pressure of an oxygen sample in mm of mineral oil if its pressure is 28.5 mm Hg? (d of mineral oil = 0.88 g/mL; d of Hg = 13.5 g/mL)

(Multiple Choice)

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Question 39

Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25°C and 753 torr. What mass of hydrogen was collected? (P_water = 24 torr at 25°C)

(Multiple Choice)

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Question 40

Showing 21 - 40 of 97

Exam 5: Gases and the Kinetic-Molecular Theory

At very high pressures (~ 1000 atm), the measured pressure exerted by real gases is greater than that predicted by the ideal gas equation. This is mainly because

According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average speed.

Ima Chemist found the density of Freon-11 (CFCl3) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the unknown?

A sample of an ideal gas has its volume doubled while its temperature remains constant. If the original pressure was 100 torr, what is the new pressure?

The rate of diffusion of a gas is inversely proportional to its molar mass.

A sample container of carbon monoxide occupies a volume of 435 mL at a pressure of 785 torr and a temperature of 298 K. What would its temperature be if the volume were changed to 265 mL at a pressure of 785 torr?

For a gas obeying Charles's Law, a plot of V versus 1/T will give a straight line passing through the origin.

"The pressure of an ideal gas is directly proportional to its absolute temperature at constant volume and number of moles" is a statement of ________________ Law.

A flask containing neon gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where the prevailing pressure is 745 torr. The mercury level in the open arm is 50. mm below that in the arm connected to the flask of neon. What is the neon pressure, in torr?

The most probable speed of an oxygen molecule in the gas phase at room temperature is 450 m/s. The root-mean-square speed (urms) is therefore

According to the postulates of kinetic-molecular theory, the average kinetic energy of gas molecules is proportional to the absolute temperature.

A ballerina weighs 103 lbs and is up on her toes with only 10.0 cm2 of her slippers in contact with the floor. What pressure is she exerting on the floor?

Assuming ideal behavior, what is the density of argon gas at STP, in g/L?

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of _____________ Law.

A 250.0-mL sample of ammonia, NH3(g), exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container?

What are the conditions of STP?

An unknown liquid is vaporized in a 273-mL flask by immersion in a water bath at 99°C. The barometric pressure is 753 torr. If the mass of the vapor retained in the flask is 1.362 g, what is its molar mass?

At moderate pressures (~ 200 atm), the measured pressure exerted by CO2 gas is less than that predicted by the ideal gas equation. This is mainly because

Mineral oil can be used in place of mercury in manometers when small pressure changes are to be measured. What is the pressure of an oxygen sample in mm of mineral oil if its pressure is 28.5 mm Hg? (d of mineral oil = 0.88 g/mL; d of Hg = 13.5 g/mL)

Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25°C and 753 torr. What mass of hydrogen was collected? (Pwater = 24 torr at 25°C)

Keys to Studying Chemistry Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Thermochemistry Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces Liquids, Solids, and Phase Changes

The Properties of Mixtures Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics Rates and Mechanisms of Chemical Reactions

Equilibrium the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics Entropy, Free Energy, and Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

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Ima Chemist found the density of Freon-11 (CFCl₃) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the unknown?

The most probable speed of an oxygen molecule in the gas phase at room temperature is 450 m/s. The root-mean-square speed (u_rms) is therefore

A ballerina weighs 103 lbs and is up on her toes with only 10.0 cm² of her slippers in contact with the floor. What pressure is she exerting on the floor?

A 250.0-mL sample of ammonia, NH₃(g), exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container?

At moderate pressures (~ 200 atm), the measured pressure exerted by CO₂ gas is less than that predicted by the ideal gas equation. This is mainly because

Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25°C and 753 torr. What mass of hydrogen was collected? (P_water = 24 torr at 25°C)