Chemistry Chapter 13

Melting Point

The temperature at which a substance changes from a solid to a liquid; the melting point of water is 0�C.

Boiling Point

The temperature at which the vapor pressure of a liquid is just equal to the external pressure on the liquid

Sublimation

The process in which a solid changes to a gas or vapor without passing through the liquid state

Evaporation

Vaporization that occurs at the surface of a liquid that is not boiling

Vaporization

The conversion of a liquid to a gas or vapor

Normal Boiling Point

The boiling point of a liquid at a pressure of 101.3 kPa or 1 atm

Kinetic Theory

A theory explaining the states of matter, based on the concept that all matter consists of tiny particles that are in constant motion.

Atmospheric Pressure

The pressure exerted by atoms and molecules in the atmosphere surrounding Earth, resulting from collisions of these particles with objects

Vapor Pressure

A measure of the force exerted by a gas above a liquid in a sealed container; a dynamic equilibrium exists between the vapor and the liquid

Barometer

An instrument used to measure atmospheric pressure

Kinetic Energy

The energy an object has because of its motion

Absolute Zero

-Absolute zero (0 K, or -273.15� C) is the temperature at which the motion of particles theoretically ceases.
-Particles would have no kinetic energy at absolute zero.
-Absolute zero has never been produced in the laboratory.

What is the difference between boiling point and normal boiling point?

-Boiling Point: The temperature at which the vapor pressure of a liquid is just equal to the external pressure on the liquid
-Normal Boiling Point: The boiling point of a liquid at a pressure of 101.3 kPa or 1 atm

What is the difference between vapor pressure and atmospheric pressure?

-Vapor Pressure: A measure of the force exerted by a gas above a liquid in a sealed container; a dynamic equilibrium exists between the vapor and the liquid
-Atmospheric Pressure: The pressure exerted by atoms and molecules in the atmosphere surrounding E

What is the difference between boiling and evaporation?

-Boiling: When a liquid is heated to a temperature at which particles throughout the liquid have enough kinetic energy to vaporize, the liquid begins to boil.
-Evaporation: Vaporization that occurs at the surface of a liquid that is not boiling. During ev

What is the difference between melting point and freezing point?

-Melting Point: The temperature at which a substance changes from a solid to a liquid; the melting point of water is 0�C.
-Freezing Point: the temperature at which a liquid changes into a solid
-The Melting and Freezing Points of a substance are the same

List the points of the kinetic theory.

1. The particles in a gas are considered to be small, hard spheres with an insignificant volume.
2. The motion of the particles in a gas is rapid, constant, and random.
3. All collisions between particles in a gas are perfectly elastic

What is the SI unit of pressure?

Pascal (Pa)

What are the units for normal atmospheric pressure?

1 atm=760 mmHg=101.3 kPa

How does normal pressure compare with pressure above/below sea level?

Pressure decreases from normal as the height above sea level increases.
Pressure increases from normal as the depth below sea level increases.

How does high/low atmospheric pressure change boiling point?

The lower the pressure the lower the boiling point. As the pressure lowers, it means it takes less vapor pressure to equal the atmospheric pressure, hence a lower boiling point.

What causes air pressure?

Atmospheric pressure results from the collisions of atoms and molecules in air with objects

Which temperature scale is directly proportional to the average kinetic energy of molecules?

The Kelvin temperature of a substance is directly proportional to the average kinetic energy of the particles of the substance.

Would average kinetic energy be higher in water that is 100�C or steam that is 100�C? in water at 90�C or water at 100�C?

Kinetic energy is directly proportional to Kelvin temperature.
100+273=373K
90+273=363K
-it would be higher in steam since steam is a gas, and gases have the highest energy
-Greater in 100 than 90 (water)

What is absolute zero?

-Absolute zero (0 K, or -273.15� C) is the temperature at which the motion of particles theoretically ceases.
-Particles would have no kinetic energy at absolute zero.
-Absolute zero has never been produced in the laboratory.

What happens to the temperature of a liquid as it evaporates? Which particles evaporate first?

As liquid evaporates, it cools. The particles that have the highest kinetic energy and temperature evaporate first.

What is dynamic equilibrium? Explain how and when dynamic equilibrium is reached?

-In a system at constant vapor pressure, a dynamic equilibrium exists between the vapor and the liquid. The system is in equilibrium because the rate of evaporation of liquid equals the rate of condensation of vapor.
-An increase in the temperature of a c

When does boiling occur? When does sublimation occur? What is the element that we saw sublimate and depose in a demonstration?

-When a liquid is heated to a temperature at which particles throughout the liquid have enough kinetic energy to vaporize, the liquid begins to boil
-The temperature at which the vapor pressure of the liquid is just equal to the external pressure on the l

If the external pressure is 200 kPa, what would the vapor pressure of water be that is boiling?

200kPa, because at boiling point, external pressure equals vapor pressure.

Which states of matter can be compressed?

Gas (Chapter 14)

How many different crystal systems are there and how do they differ?

-7: Galena, Zircon, Topaz, Gypsum, Amazonite, Tourmaline, Calcite
-Crystal Systems differ in: angles of the faces and number of edges of equal length on each face

List the three allotropes of carbon and describe many ways they differ.

Diamond: Each carbon atom in the interior of the diamond is strongly bonded to four others. The array is rigid and compact.
Graphite: The carbon atoms are linked in widely spaced layers of hexagonal (six-sided) arrays.
Fullerene: In buckminsterfullerene,

Sketch a phase graph. Label: solid, liquid, gas, temperature, pressure, normal melting point and normal boiling point, triple point. Define triple point.

LOOK TO NOTES FOR GRAPH
Triple Point: the point on a phase diagram that represents the only set of conditions at which all three phases exist in equilibrium with one another

Explain why it takes longer to boil an egg in Denver than it does in Alton.

-The temperature at which the vapor pressure of the liquid is just equal to the external pressure on the liquid is the boiling point (bp).
-At a lower external pressure, the boiling point decreases
-At a higher external pressure, the boiling point increas

Write three pressure unit conversion problems using atm, mm Hg, and kPa. Solve them.

1 atm=760 mmHg=101.3 kPa