Chapter 13 Review

Video Review

Key Concept Summary

TA Summary

Vocabulary

The tiny constituent particles of which matter is composed.

A measure of average kinetic energy of the molecules that make up an object.

The constant, irregular motion of very fine particles suspended in a fluid and observed with a microscope.

The transfer of microscopic kinetic energy between two solid objects (a hot one and a cold one) that are in physical contact with each other.

Model that explains the behavior of gases observed by Maxwell.

Force per unit area.

True/False

Pressure in a hot tire is greater than the pressure when the tire is cold.

True False

For a given material, the solid state has a higher internal energy than the gaseous state.

True False

The molecular model is limited in that it cannot explain the color of an object.

True False

Heat is the amount of energy associated with electrical potential energy.

True False

In the molecular model, molecules are assumed to move according to special laws of motion which are different from how large objects move.

True False

According to Maxwell, all of the gas molecules in a balloon are traveling at the same speed.

True False

Analysis

Between two objects, heat always travels

from a cooler to a warmer object. from a warmer to a cooler object. randomly between the two objects regardless of their temperature. Heat doesn't travel between objects.

For nearly all substances, the density of physical states increases in which order?

solid, gas, liquid liquid, gas, solid solid, liquid, gas gas, liquid, solid

The average distance between molecules in states of matter (solid, liquid, gas) increase in which order?

Gas, liquid, solid Liquid, solid, gas Solid, liquid, gas

If a large bucket of water and a small bucket of water have the same temperature,

both have the same total internal energy. both have the same total molecular kinetic energy. the average molecular speed is the same for both. both have the same total energy. the water molecules in the small bucket are moving faster than those in the large bucket.

Heat conduction occurs from a warm room through a closed window on a cold day because

the molecules in the glass window are moving faster than those in the air inside the room. fast molecules go through the window to the outside. slow molecules enter the room from the outside. slow molecules tend to transfer energy to faster one with which they collide. fast molecules tend to transfer energy to slower ones with which they collide.

Evaporation of water from the skin has a cooling effect. This is because

the most massive water molecules escape into the surrounding atmosphere. water molecules with the greatest speed escape into the surrounding atmosphere. water molecules with least kinetic energy escape into the surrounding atmosphere. the surrounding atmosphere transfers its energy into the water. the least massive water molecules escape into the surrounding atmosphere.

Which of the following best describes the behavior of molecules in the molecular model?

molecules are to small to be detected. Molecules are large amorphous blobs that move in random directions with no apparent forces on them. The gas molecules are very small indivisible objects that move according to Newton's laws and bounce off of each other and the walls of their container.

Temperature is a measurement of:

the average speed of molecules the state of matter molecules are in the average kinetic energy of the molecules the amount of entropy transferred to the molecules

Gas pressure is caused by:

kinetic energy being transferred from molecules with high energy to those with lower energy an increase in the motion of the walls of the container. the collisions of gas molecules with the walls of the container. the large amount of space taken up by the gas molecules.

Which of the following will increase the air pressure in a car tire?

increasing the temperature increasing the volume decreasing the number of molecules decreasing the average kinetic energy of the molecules

When a gas molecule collides with a rigid wall, how does the force it exerts on the wall compare to the force the wall exerts on the molecule?

The force on the wall is larger. The force on the molecule is larger. The two forces are equal.

Suppose two identical airtight containers are connected to each other by a thin tube. They both start out at room temperature, but one container is placed in a pan of boiling water, while the other is placed in a container of ice water. What happens to the air trapped in the containers?

Some of the molecules in the hot container will move into the cold container. The hot container will end up with fewer molecules, but the pressures will be equal. The air in the hot container will be moving faster. So, the pressure in the hot container will be higher than the pressure in the cold container, but the number of molecules in each container will be equal. The pressure, temperature, and number of atoms in each container must be equal. As the average of the temperature of ice water than the temperature of boiling water is larger than room temperature, the final pressure and temperature will be higher than it was at room temperature. Placing the containers in ice water and boiling water will change the temperature of the air inside those containers, but will have no effect on the pressure.

Air is made up of several different types of molecules. Which move the fastest.

The molecules with the largest mass. The molecules with the largest volume. The molecules with the smallest mass. The molecules with the smallest volume.

As an ice cube changes from a solid at 0 °C to a liquid at the same temperature, what happens to the kinetic energy of the molecules?

Their kinetic energy increases. Their kinetic energy decreases. Their kinetic energy stays the same.

If the volume of a gas is decreased, what happens to the temperature of that gas?

It increases. It decreases. It stays the same. It is impossible to tell from the information give.

Two identical containers of gas are at identical pressures, but container 1 has twice as many gas molecules inside as container 2. What can you conclude about the containers?

The molecules in container 1 are half as large as the molecules in the second container. The molecules in container 1 move at 1/2 the speed of the molecules in container 2. The molecules in container 1 have 1/2 the energy of the molecules in container 2. The molecules in container 1 have 1/2 the mass of the molecules in container 2.

What would Robert Brown have observed if he increased the sample temperature while looking through his microscope?

He would have found that the pollen grains twitch and jerk more rapidly. There would be no change in the motion on the pollen grains. He would have found that the pollen grains twitch and jerk more slowly.

Free Response

Using the Molecular Model, explain why gases readily change volume when pressure is applied, while liquids and solids do not change volume appreciably, unless under enormous pressure.
Use the Molecular Model to explain each observation:
- The density of solid nitrogen molecules is greater than the density of nitrogen molecules in air.
- Heat flows from hot objects to colder ones.
- Perfume spilled at one end of a room can be smelled at the other end after a few seconds.
Your neighbor knocks at your door and asks you to explain something. She bought a helium-filled balloon for her daughter in a warm grocery store. When she put it in her car on a cold January day, the balloon shrank and she thought the balloon had sprung a leak. But the balloon returned to its original size when she took it into her warm house. What explanation can you give based on the molecular model?
Figure 13.5 in the textbook illustrates how the distribution of molecular speeds varies with mass of the gas particles for helium, nitrogen, and argon. Helium atoms have a mass of 4 units, nitrogen molecules have mass 28, and argon atoms have mass 40. Sketch what the graph might look like for oxygen molecules, if oxygen molecules have a mass of 32. The most important characteristics of the distribution are the most popular speed, the fraction of molecules with that speed, and the overall width of the distribution.

Do the following:

Identify the portions of the graph in Figure 13.8 in the textbook where only one state of matter is present (e.g., only solid, only liquid, or only gas). Describe what happens to the temperature during these portions of the graph as time and total energy increase. (If you were looking at a thermometer, what would you see happening?) From your observation of the temperature change, what can you conclude about the kinetic energy of the matter during these processes? That is, does the kinetic energy increase or decrease as the total energy increases?

Now look at the segments when two states of matter are present (solid & liquid, liquid & gas). Describe the temperature behavior within these segments as time and total energy increases. What can you conclude about the change in kinetic energy based upon the temperature behavior?

Hopefully, you have identified stages in the process where the kinetic energy is constant but the total energy is increasing. How can you explain this? Think about what happens to the average distance between molecules as you go from state to state. What kind of energy is associated with the relative positions of particles?

The details of Figure 13.8 apply to changes of state for many substances other than water. Pick one of the substances (other than water) in Table 12.1 in the textbook and sketch a graph like Figure 13.8 for your substance. Things to consider: At what temperatures will you have plateaus? Between what temperatures will you have sloping lines?