Chemistry Test

125 K

-148 C

100 K

-173 C

96 K

-177 C

6 K

-267 C

273 K

0 C

What is the average kinetic energy of any substance at 0 K?

0 J

At what temperature and pressure can all three phases of water exist simultaneously?

0.01 C, 4.58 mmHg

For this question, use the main assumptions of the Kinetic Molecular Theory of gases: 1. Gases are made up of molecules which are relatively far apart. 2. The molecules are in motion at high speeds. 3. The molecular collisions are perfectly elastic. 4. Increase in temperature increases the kinetic energy of the molecules. Which of the above assumptions accounts for the compressibility of gases as compared to liquids and solids?

1

The following are the main assumptions of the Kinetic Molecular Theory of gases: 1. Gases are made up of molecules which are relatively far apart. 2. The molecules are in motion at high speeds. 3. The molecules are perfectly elastic. 4. Increase in temperature increases the kinetic energy of the molecules. The assumption that accounts for the great compressibility of gases compared to liquids and solids is:

1

Each degree on the Kelvin scale equals:

1 C

In the field of chemistry, standard temperature and pressure conditions are:

1 atm, 273 K

List two assumptions of the Kinetic Molecular Theory.

1. All gasses consist of molecules. 2. The attractive forces between molecules are very weak in gases, but depend on the distance between them.

The volume of a diver's lungs was measured to be 3.6 liters at 1.0 atmosphere of pressure. As the diver descends, assuming that no air is lost, the pressure increases to 3.2 atmospheres. What is the new lung volume?

1.1 L

What volume will 1.25 liters of carbon dioxide occupy at 50.0°C if the pressure changes from 0.865 atm to 0.820 atm?

1.32 L

If 21 mL of gas are subjected to a temperature change from 10.0°C to 120°C and a pressure change from 1.0 atm to 15 atm, the new volume is: (Be sure to use the correct number of significant figures.)

1.9 mL

Hydrogen chloride gas is shipped in a container under 5,100 mm Hg of pressure that occupies 20.1 liters at 29°C. How many liters of gas would be produced at STP?

120 L

To test the effectiveness of a gunpowder mixture, 1 gram was exploded under controlled STP conditions, and the reaction chamber was found to expand to 310 cm3. What volume would these gases occupy at the temperature produced by an uncontrolled explosion (2,200°C) and 2.1 atmospheres of pressure?

1300 cm^3

436 K

163 C

translation, vibration, rotation

2

For this question, use the main assumptions of the Kinetic Molecular Theory of gases: 1. Gases are made up of molecules which are relatively far apart. 2. The molecules are in motion at high speeds. 3. The molecular collisions are perfectly elastic. 4. Increase in temperature increases the kinetic energy of the molecules. Which of the assumptions explains the pressure which a gas exerts?

2 and 4

The formula of a compound indicates all of the following except:

22.4 L

Suppose that on a hot and sticky afternoon in the spring, a tornado passes over the high school. If the air pressure in the lab (volume of 180 m3) was 1.1 atm before the storm and 0.85 atm during the storm, to what volume would the laboratory try to expand in order to make up for the large pressure difference outside?

230 m^3

What is the approximate vapor pressure when the liquid water boils at about 50°C? (mm Hg)

230 mmHg

If a balloon containing 1,200 L of gas at 25°C and 760 mm Hg pressure ascends to an altitude where the pressure is 380 mm Hg and the temperature is 54°C, the volume will be: (Be sure to use the correct number of significant figures.)

2600 L

A compressor takes 0.50 m3 of a gas at 33°C and 760 mm Hg and compresses it to 0.10 m3, cooling it to -55°C at the same time. What is the pressure of the gas at these new conditions?

2700 mmHg

A balloon was partially filled with helium gas at room temperature. It occupied 4.0 liters of volume at 700.0 mm Hg atmospheric pressure. When the balloon was released, it traveled upward until it burst at 99 mm Hg atmospheric pressure. (Neglect any force exerted to stretch the rubber balloon.) What was the volume of the balloon when it burst?

28 L

18 C=

291 K

For this question, use the main assumptions of the Kinetic Molecular Theory of gases: 1. Gases are made up of molecules which are relatively far apart. 2. The molecules are in motion at high speeds. 3. The molecular collisions are perfectly elastic. 4. Increase in temperature increases the kinetic energy of the molecules. The idea that no energy is lost when gas molecules hit the walls of a container or each other is explained by

3

What is the Kelvin temperature for 30 C?

303 K

63 C=

336 K

A balloon of helium was put in the freezer at -23°C. Its volume at this temperature was 2.5 liters. It was removed from the freezer. Eventually, it reached a temperature of 177°C. What would its volume be at this temperature? (Neglect any force used to stretch the rubber balloon.)

4.5

A 1.50-liter sample of dry air in a cylinder exerts a pressure of 3.0 atmospheres at a temperature of 25°C. Without change in temperature, a piston is moved in the cylinder until the pressure in the cylinder is reduced to 1.0 atmosphere. What is the volume of the gas? (Be sure to use the correct number of significant figures.)

4.5 L

A balloon is filled with helium at sea level. The volume was measured to be 3.1 liters at a pressure of 0.97 atmosphere. If the balloon is released, it drifts upward. At a height of 4 kilometers, the pressure is measured to be 0.61 atmospheres. What is the volume of the balloon?

4.9 L

143 C

416 K

The following are the main assumptions of the Kinetic Molecular Theory of gases: The assumption that explains Charles's Law is :

4: Increase in temperature increases the kinetic energy of the molecules.

The volume of a gas is 605 liters at 27.0°C. The new temperature is -3.0°C. What is the new volume? (Remember to convert temperatures to the Kelvin scale.)

545 L

283 C=

556 K

The original conditions in a container filled with gas at constant temperature are 183 mL and 310 mm Hg. The desired new volume is 90.6 mL. What pressure should be applied?

630 mmHg

Ten grams of a gas occupies 12.5 liters at a pressure of 42.0 cm Hg. What is the volume when the pressure has increased to 75.0 cm Hg?

7.00 L

1 atm=

760 mmHg

A 25-liter sample of steam at 100°C and 1.0 atm is cooled to 25°C and expanded until the pressure is 19.71 mm Hg. If no water condenses, calculate the final volume of the water vapor.

770 L

A tire has a pressure of 780 mmHg at 27 C. If the tire is heated to 47 C on hot pavement, the new pressure will be:

830 mmHg

573 C

846 K

A diesel engine's piston compresses 16 cm3 of fuel-air mixture into 1 cm3. The pressure changes from 1 atmosphere to 48 atmospheres. If the initial temperature of the gas was 305 K, what was the final temperature? Note: As long as the units for pressure and volume are the same on both sides of the equation, they will cancel. Temperature, however, must be in units of kelvin. Be sure to use the proper number of significant figures.

900 K

In the combustion chamber of an engine, the initial volume is 450 cm3 at a pressure of 1.0 atmosphere. If the piston displaces 402 cm3 of the total, what is the resulting pressure in the combustion chamber? (Assume negligible temperature change.) Hint: Calculate the new volume by subtracting the amount of space the piston takes up from the initial volume.

94 atm

Air is evacuated from the chamber and the vapor pressure is regulated by the pump. Indicate the state of the H2O for the following condition. Temp. = 90°C Pressure = 350 mm Hg

All the water has evaporated.

Why do cake mixes have high elevation instructions?

Atmospheric pressure is less at higher elevations.

When the volume changes from 63.5 mL to 69.2 mL, what is the final pressure if the initial pressure was 735 mm Hg pressure? Law used:

Boyle's Law

gases such that as pressure increases, volume decreases by the same fraction of change; temperature and number of molecules remain constant

Boyle's Law

relates pressure and volume

Boyle's Law

Which temperature conversion is correct?

C=K-273

What will be the new volume of 250 mL sample of gas at 300 K and 1 atm fi heated to 350 K at 1 atm? Law used:

Charles's Law

relates volume and temperature

Charles's Law

Carbon dioxide is in a steel tank at 20°C, 10 liters and 1 atm. What is the pressure on the gas when the tank is heated to 100°C? Law used:

Combined Gas Law

What temperature will 215 mL of a gas at 20°C and 1 atm pressure attain when it is subject to 1.5 atm of pressure? Law used:

Combined Gas Law

What volume will 1.56 liters of a gas at 27°C and 745 mm Hg of pressure occupy at 100°C and 700 mm Hg of pressure? Law used:

Combined Gas Law

Two compounds are standing at the same temperature. Compound "A" is evaporating more slowly than compound "B." According to the Kinetic Molecular Theory, which assumption can be made?

Compound B may have a lower molecular weight.

Examine the graph below: Choose which of the following is NOT true:

Condensation occurs at 0 C.

How is condensation explained by the Kinetic Molecular Theory?

Cooling reduces particle motion, resulting in coalescence by attractive forces

All the molecules of a substance possess the "average kinetic energy" value.

False

In a closed system, the volume of a gas is not related to the volume of its enclosure.

False

Real gases do not exist.

False

Researchers have now been able to cool substances to absolute zero.

False

Solids can often diffuse into a liquid but cannot diffuse into another solid.

False

Temperature is a direct measurement of the energy contained in a substance.

False

The "particles" of a gas are actually protons or electrons.

False

The freezing temperature of water is zero on both the "K" and "C" scales.

False

The scientific study of the behavior of substances near 0 K is called pyrogenics.

False

If Charles's Law of V/T=k were represented in graphical form, what it would look like?

Graph with e, V, T and the line will go diagonal and up from left to right.

In order to use the gas laws, all temperatures must be in the _______ scale.

Kelvin

The temperature scale that starts with absolute zero is the _______ scale.

Kelvin

matter is continuously in motion

Kinetic Molecular Theory

the theory that attempts to explain gas behavior at the molecular level

Kinetic Molecular Theory

The mathematical formula for Boyle's Law is:

P_1V_1=k

Which of these expressions are correct variations of the Combined Gas Law?

P_1V_1T_2=P_2V_2T_1 P_2=P_1(T_2/T_1)(V_1/V_2)

When can liquid water remain above 100 C?

Pressure must be greater than 760 mmHg.

According to the phase diagram for water, how is the state of water determined?

Read the phase at the intersection of any given temperature and pressure.

Which of the following statements is true?

Several variables of a gas often change simultaneously.

Which of these expressions are correct variations of the Combined Gas Law?

T_1=T_2(P_1V_1/P_2V_2) V_2=V_1(T_2/T_1)(P_1/P_2)

When the gas shown in the Energy Distribution diagram is heated to "T_2," what has happened?

The average kinetic energy has increased. More molecules have a higher energy level.

Whether a substance is a gas, liquid, or solid is dependent on the natural attractive forces between molecules and

The collisions between the molecules. The extent of molecular motion as determined by the average KE and temperature.

Click on the graph that best represents the relationship between altitude and water's boiling point.

The curve is to the left of the graph.

Which of these statements describes this mathematical equation? P_1V_1/T_1=k

The final pressure of a gas is inversely proportional to the volume change and directly proportional to temperature change.

Why don't the data points of the graph in the lesson extend to the horizontal axis?

The has liquefied at the data point.

Why does an evaporating liquid cool down according to the Kinetic Molecular Theory?

The highest velocity molecules are lost.

A man drove his car through the Nevada desert one day when the temperature was over 100°F. When he started the trip, the gas station attendant found the tire to be 32 lb/in2. When he filled up with gas after crossing the desert, an attendant found the tire pressure to be 38 lb/in2. What is the best explanation for the increase in tire pressure?

The temperature in the tire increased, causing an increased tire pressure.

We know that standard pressure is one atmosphere, or 760 millimeters of mercury. This pressure results from the weight of gas molecules in the atmosphere. As a diver enters the water, he is subject to both water pressure and air pressure. Because water is much denser than air, the pressure increases rapidly as the diver descends. At the depth of 34 feet in fresh water, the diver is experiencing 2 atmospheres of pressure (one from air pressure and one from the 34 feet of water). For every additional 34 feet the diver descends he will be under an additional atmosphere of pressure. Since water pressure is proportional to depth, how many atmospheres of pressure would a diver experience at 102 feet? Why wouldn't this pressure squash the diver? Answering this second question may be easier if you think of the reason a person on land is not squashed by one atmosphere of pressure. Explain your answer in detail.

There would be 4 atmospheres of pressure that the diver would experinece at 102 feet. He would experince the air pressure and the 3 atmospheres of pressure from the 102 feet. The diver's scuba tank would provide the right amount of volume that his lungs require for the atmosphere of pressure he is at. His regulater would allow the volume in his tank to change according to the increasing pressure.

A device used to measure the atmospheric pressure is the barometer.

True

A device used to measure the pressure of an enclosed gas is a manometer.

True

An ideal gas does not exist.

True

Gases with high molecular weights diffuse more slowly than gases with lower molecular weights.

True

In an open system, the vapor pressure is equal to the outside air pressure at a liquid's boiling point.

True

In an open system, the vapor pressure is equal to the outside air pressure.

True

The "particles" of gases are actually atoms, or molecules.

True

The scientific study of the behavior near 0 K is called cryogenics.

True

The correct form(s) of the formula for Charles's Law is (are):

V/T=K T_1/T_2=V_1/V_2

A 1.50-liter sample of dry air in a cylinder exerts a pressure of 3.00 atmospheres at a temperature of 25°C. Without change in temperature, a piston is moved in the cylinder until the pressure in the cylinder is reduced to 1.00 atmosphere. The volume of the gas is:

V=(1.50)(3.00)/(1.00)=4.50L

Which of these equations are correct? Select all that apply.

V_2=k/P_2 V_2=P_1V_1/P_2 P_2=P_1(V_1/V_2)

Most full scuba tanks have a pressure of between 1,800 p.s.i. and 3,000 p.s.i. (pounds per square inch). Approximately 70 to 85 cubic feet of air has been squeezed into the tank. When a diver takes his air tank to be refilled, the dive shop will hook his tank to a compressor with a pressure hose and place his tank in a tub of water while it is being filled. What reasons can you give for placing the tank in water? While thinking about this, keep the gas laws in mind. Explain your answer in detail.

When more volume is added to the tank, then the pressure will rise and create heat. If the surrounding atmosphere is warm, then the tank could expand too much. If the surrounding atmosphere of the tank is colder than the heat inside the tank, then the heat and the pressure will slow down and not cause the tank to expand.

The temperature-volume relationship shown in the graph in the lesson represents:

a direct linear function

A compound consisting of atoms of large atomic mass is more likely to require:

a higher temperature to liquefy

The graph above can be extrapolated to determine:

absolute zero

Boyle's Law for gases is:

accurate for most gases in most temperature ranges

The instrument pictured below is a (it is the tall tube)

barometer

a device for measuring atmospheric pressure

barometer

An open empty can is heated, then capped and removed from the heat. The can will:

collapse

What is meant by "elastic collisions"?

collision and rebound without loss of energy

Click on the graphic to choose the correct relationship on the graph. R = diffusion rate of gas MW = molecular weight

curve to the left of the graph

Temperature ____________ as the average kinetic energy of a gas decreases.

decreases

The process of intermingling atoms (molecules) from one substance into another.

diffusion

the intermingling of one substance within another

diffusion

Vapor pressure is __________ related to the temperature of the liquid.

directly

Vapor pressure is ____________ related to the temperature of the liquid.

directly

Kinetic energy is:

directly proportional to mass and velocity

According to the Kinetic Molecular Theory, the absolute temperature of a gas is directly related to average molecular kinetic

energy

a dynamic situation when the number of molecules leaving the liquid is greater than the number returning

evaporation

occurs at phase equilibrium

evaporation = condensation

The dashed segment of the plotted experiment in the graph in the lesson is called an:

extrapolation

Solids can often diffuse into a liquid, but a solid cannot diffuse into another solid.

false

Which phase change temperatures are identical on the phase diagram?

freezing point-melting point boiling point-condensation point

rapid, random motion

gas

variable volume; variable shape

gas

condensation

gas changing to a liquid

vibrate, rotate, and translate

gas particles

The Kinetic Molecular Theory helps explain relationships between:

gases, energy, temperature, phases

When the pressure of a gas doubles, the volume:

halves

Real gases may be expected to deviate from Charles's Law at ______________ pressures near the ______________ temperature.

high liquefaction

required for evaporation

high speeds

An imaginary gas which perfectly obeys the gas laws is called

ideal

an imaginary gas which perfectly obeys the gas laws

ideal gas

A gas occupies 210 mL at -73°C. To have the same gas occupy 360 mL, should the temperature be increased or decreased? What is the new temperature?

increased 340 K

Temperature ____________ as the average kinetic energy of a gas increases.

increases

Choose the incorrect answer below concerning absolute zero.

is equal to 0 C

One of two of more atoms having the same number of protons but different numbers of neutrons

isotope

determined by mass and speed

kinetic energy

the energy of motion which is represented as K.E.=1/2mv^2 where m=mass, and v=velocity of the particles in motion

kinetic energy

A sample of gas occupies 9.0 mL at a pressure of 500 mm Hg. A new volume of the same sample is at 750 mm Hg. Is the new pressure smaller or larger than the original? Therefore, is the new volume larger or smaller than 9.0 mL? What is this new volume?

larger smaller 6.0 mL

fixed volume; variable shape

liquid

rotation and vibration

liquid

vibrate and rotate

liquid particles

Under what conditions will deviations from the "ideal" gas be expected? Select all that apply.

low temperatures high pressure

What conditions cause deviations from the "ideal" gas? Select all that apply.

low temperatures high pressure

The reduced vapor pressure at the high altitudes causes a liquid to boil at a _________ temperature.

lower

The instrument pictured below is a (it is the "U" tube)

manometer

a device used to measure the pressure of an enclosed gas

manometer

Which molecules shown in the Energy Distribution Graph are likely candidates for evaporation?

molecules under the right end of the curve

A man went to a gas station and asked the attendant to inflate the low front tire. When the attendant finished, the constant(s) for the system was (were):

none of the above

solid, liquid, gas

order of increasing kinetic energy

graph showing how phases are affected by changes in temperature or pressure

phase diagram

the state achieved when the exchange of molecules between two phases occurs at the same rate

phase equilibrium

The total force of contained gas molecules striking and pushing against the walls of their container

pressure

Which variable is held constant when testing for the thermal expansion relationship of a gas?

pressure

caused by collisions with container walls

pressure

Boyle's Law represents the relationship of volume as pressure is changed. What are the variables of Boyle's Law?

pressure and volume

Boyle's Law shows an inverse relationship between:

pressure and volume

What is the primary cause of diffusion?

random internal motion of atoms and molecules

Gas pressure in a closed system is caused by:

resultant force of all collisions with the container walls

Gas pressure in a closed system is cause by:

resultant force of all combined collisions

fixed volume; fixed shape

solid

low energy

solid

oscillation about a fixed point

solid

vibrate slowly in fixed positions

solid particles

an indicator of average kinetic energy

temperature

measure of average kinetic energy

temperature

What two variables are held constant when testing Boyle's Law in a manometer?

temperature mass of gas

Boyle's Law represents the relationship of volume as pressure is changed. The constants of Boyle's Law are

temperature and number of molecules of gas

Whether a substance is a gas, liquid, or solid is dependent on the natural attractive forces between molecules and

the collisions between the molecules. the extent of molecular motion as determined by the average KE and temperature.

Absolute zero is _________.

the lowest possible temperature of a gas

The pressure of an enclosed gas depends on:

the number of molecules in a unit volume and their average kinetic energy

According to the Kinetic Molecular Theory, as the volume of a gas increases:

the number of particle impacts per unit area decreases

In order for a high temperature boiler or steam engine to produce superheated water, or steam:

the system must be sealed and become pressurized able atmospheric pressure

When using a manometer to check Boyle's Law, why is the pressure changed slowly?

to avoid changing the gas temperature

the temperature and pressure at which all three phases exist simultaneously

triple point

According to Charles's Law, which two variables are directly proportional?

volume and temperature

The following is a correct statement of Charles's Law: The volume of a gas varies directly with the absolute temperature under the conditions of constant pressure.

yes

Which temperature conversion is correct?

°C = K - 273