Chemistry: States of Matter & Phase Changes Review

Name ______

Matching – Choose the answer which best fits the description.

A. FreezingF. BoilingK. Absolute zero

B. CondensationG. Direct relationshipL. Kelvin

C. DiffusionH. Kinetic EnergyM. Melting

D. FluidI. SublimationN. Inverse relationship

E. STPJ. EvaporationO. Barometer

_____1. Any substance that can flow

_____2. Vaporization that occurs throughout a liquid being heated

_____3. A liquid changing to a solid

_____4. A solid changing to a liquid

_____5. Energy of motion

_____6. Gas changing to a liquid

_____7. The change of a solid directly to a gas

_____8. Movement of particles from an area of high concentration to an area of low concentration

_____9. In gases, the relationship between pressure and volume is this

_____10. The temperature at which all motion theoretically stops

_____11. The conversion of a liquid to a gas at the surface of a liquid that is not boiling

_____12. The temperature scale used for all gas laws

_____13. Instrument used to measure atmospheric pressure

_____14. Standard temperature (0°) and pressure (1 atm)

_____15. In gases, the relationship between volume and temperature is this

_____ 2. Which of the following changes would increase the pressure of a gas in a closed container?

I. Part of the gas is removed.

II. The container size is decreased.

III. Temperature is increased.

a. I and II only

b. II and III only

c. I and III only

d. I, II, and II

_____ 3. A real gas behaves most nearly like an ideal gas

a. at high pressure and low temperaturec. at low pressure and low temperature

b. at low pressure and high temperatured. at high pressure and high temperature

The heating curve shown above is a plot of temperature vs time. It represents the heating of

substance X at a constant rate of heat transfer. Answer the following questions using this

heating curve:

______1. In what part of the curve would substance X have a definite shape and definite volume?

______2. In what part of the curve would substance X have a definite volume but no definite shape?

______3. In what part of the curve would substance X have no definite shape or volume?

______4. What part of the curve represents a mixed solid/liquid phase of substance X?

______5. What part of the curve represents a mixed liquid/vapor phase of substance X?

______6. What is the melting temperature of substance X?

______7. What is the boiling temperature of substance X?

Answer the following questions.

1. The molar heat of vaporization for water is 40.79 kJ/mol. How much energy would be required to vaporize 5.00 mol of water?

2. Find the molar heat of vaporization for 3.21 mol of substance that absorbs 28.4 kJ of energy when it changes from a liquid to a gas.

3. How many calories are given off when 50 g of water at 0oC freezes? (ΔHfus = 79.72 cal/g)

4. How many joules of energy are needed to boil 90 grams of water at its boiling point? Assume that the molar heat of vaporization of water is 41 kJ/mol.

5. How much heat is released when 432 g of water (Cp = 4.18 J/g · °C), cools from 71°C to 18°C?

6. A 75 g piece of an unknown substance undergoes a temperature increase of 16°C after absorbing 600 Joules of heat. What is the specific heat of the substance?

7. If a piece of gold (Cp = 0.129 J/g · °C) with a mass of 45.5 g and a temperature of 80.5°C is dropped into 192 g of water at 15°C, what is the final temperature of the system?

Refer to the phase diagram below when answering the questions:

1)On the diagram, label the following: Solid, liquid, gas/vapor, triple point, critical point

2)What is the boiling point of this substance at 50 atm? ______

3)What is the freezing point of this substance at 50 atm? ______

4)If I had a quantity of this substance at a pressure of 45 atm and a temperature of 3000 C and lowered the temperature to 200K, what phase transition(s) would occur?

5)At what temperature do the gas and liquid phases become indistinguishable from each other?