Unit Test — Unit test Answers

25 verified answers1 views
1
Free Preview

This heating curve is produced when a certain substance is heated.Which best compares the particles of the substance when it is in region 1 with the particles of the substance when it is in region 3?

Question illustration
A
The particles are slower in region 3.
B
The particles are more orderly in region 1.
C
The particles have more kinetic energy in region 1.
D
The particles have less freedom of motion in region 3.
2
Free Preview

Which best defines partial pressure in a mixture of gases?

A
pressure that is exerted by all the gases of a mixture on the container
B
pressure that is exerted by one gas as if it occupied a container by itself
C
half of the pressure that is exerted by the gases of a mixture on the container
D
sum of the individual pressures that are exerted by two or more gases
3

Bromine gas in a container is heated over a flame. What happens to the average kinetic energy of the bromine particles?

A
It decreases rapidly.
B
It increases quickly.
C
It remains the same.
D
It decreases slowly.
4

Which of the following best identifies where long-range order would be found?

A
in amorphous solids
B
in crystalline solids
C
in thermal plasmas
D
in nonthermal plasmas
5

Which device involves the use of plasma in technology?

A
arc welder
B
diesel engine
C
a car radio
D
battery-operated flashlight
6

Which statement best explains why heating a liquid affects its viscosity?

A
The molecules move faster at higher temperatures and overcome attractions more easily.
B
The molecules move faster at higher temperatures, and the attractions between them increase.
C
The molecules move slower at higher temperatures and overcome attractions more easily.
D
The molecules move slower at higher temperatures, and the attractions between them decrease.
7

The particles of a gas inside a balloon are experiencing an increase in their average kinetic energy and the number of collisions with the wall of the balloon. What is the most likely outcome?

A
higher gas pressure inside the balloon
B
higher air pressure outside the balloon
C
a decrease in gas temperature inside the balloon
D
a large increase in air temperature outside the balloon
9

Malia was able to make a paperclip float on the surface of water. What will most likely happen to the paperclip if a drop of dishwashing detergent is added near it?

A
Soap is a surfactant that increases the intermolecular forces of water allowing the paperclip to continue to float.
B
Soap makes the water less viscous making the paperclip sink.
C
Soap is a surfactant that disrupts the intermolecular forces of water making the paperclip sink.
D
Soap makes the water more viscous allowing the paperclip to continue to float.
12

Which statement can best be concluded from the ideal gas law?

A
The product of pressure and volume of an ideal gas is proportional to the absolute temperature.
B
All collisions between atoms or molecules are perfectly elastic and are not the result of any attractive forces.
C
The temperature, pressure, and volume of a gas are all related.
D
The behavior of a gas under real conditions does not obey the ideal gas law.
14

Which is the best example of immiscible liquids?

A
two polar liquids that have high surface tensions
B
a polar liquid and a nonpolar liquid that have low surface tensions
C
two nonpolar liquids that can dissolve into one another
D
a polar liquid and a nonpolar liquid that do not dissolve into one another
15

Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state compare with the temperature at the end of the change?

Question illustration
A
The temperature is always lower.
B
The temperature is always the same.
C
The temperature is usually lower.
D
The temperature is usually higher.
16

Which is an aspect of the kinetic-molecular theory and can be used to explain the behavior of plasmas?

A
Particle spacing can allow a very high density.
B
Particle kinetic energy is independent of temperature.
C
Particles vibrate quickly in stationary positions.
D
Particles exchange energy through elastic collisions.
18

Water’s molar mass is 18.01 g/mol. The molar mass of glycerol is 92.09 g/mol. At 25°C, glycerol is more viscous than water. Which substance has the stronger intermolecular attraction?

A
glycerol because it has a larger molar mass
B
glycerol because it is more viscous and has a larger molar mass
C
water because it has a lower molar mass
D
water because it is less viscous and has a lower molar mass
19

Which change of state involves a release of energy?

A
boiling
B
condensation
C
melting
D
sublimation
20

A perfume bottle is dropped in the corner of a room and it shattered. The odor of the perfume can be detected on the other side of the room. Which statement best describes this observation?

A
Particles are moving from regions of high concentration to low concentration.
B
Particles are moving from regions of low concentration to high concentration.
C
Particles are moving through a small opening into a smaller volume.
D
Particles are moving through a small opening into a larger volume.

Did you find these answers helpful?

Unit Test — Unit test Answers…