1. Unit 2 Test Review

2. When an iron nail is ground into powder what happens to it’s mass?
It stays the same

3. The volume of a gas is doubled while the temperature is held constant
The volume of a gas is doubled while the temperature is held constant. How does the gas pressure change?
It is reduced by one half.

4. A sample of gas occupies 17 mL at
–112o C What volume does the sample occupy at 70o C?
17 mL X 343 K
161 K
= 36 mL

5. What would happen to the pressure with the following change?
The temperature is increased.
Pressure increases

6. What would happen to the pressure with the following change?
The volume of the container is increased.
Pressure decreases

7. What would happen to the pressure with the following change?
More of the gas is added to the container.
Pressure increases

8. What would happen to the pressure with the following change?
The average kinetic energy of the gas in increased.
Pressure increases

9. What method would you use to determine the average kinetic energy of the molecules of water in a glass.?
measure the water’s temperature

10. Describe the movement of ideal gases according to the kinetic theory
Motion is constant, random, and rapid

11. 20-kg sample of a substance as it is cooled at a constant rate
During which intervals on the graph is the average kinetic energy of the molecules in the sample decreasing?
A, C and E

12. How can you be CERTAIN that a chemical change has taken place?
Check the composition of the sample before and after the change.

13. What distinguishes a substance from a mixture?
Mixtures can be separated physically, while compounds cannot

14. Standard conditions when working with gases are defined as ____.
0o C and kPa

15. What causes gas pressure in a container such as a helium balloon?
The collisions of fast-moving gas particles on the walls of the container

16. How are average kinetic energy of the particles and temperature of a substance related?
Kinetic energy is directly proportional to the temperature of the substance
Temperature is a measure of the average kinetic energy of the particles of a substance

17. Explain equilibrium vapor pressure.
In a closed container the rate of evaporation will equal the rate of condensation

18. As the temperature of the gas in a balloon decreases, what happens to each of the following?
volume
pressure
kinetic energy
decreases

19. Which state of matter is characterized by having an indefinite shape, but a definite volume?
liquid

20. Which state of matter is most dense?
solids

21. Which state of matter have the strongest intermolecular attractions
solids

22. Which state of matter has the most space between their particles
gas

23. Which state of matter expands when heated and is easy to compress?
gas

24. Describe an ideal gas
Small particles with no volumes or intermolecular attractions

25. Classify the following:.
table salt
air
nitrogen
gold
substance /compound
mixture / homogenous
substance / element

26. Classify the following:.
substance /compound
mixture / homogenous
mixture / heterogenous
substance / element
water
stainless steel
noodle soup
oxygen

27. Identify the following as a homogeneous mixture or heterogenous mixture?
milk
oil and vinegar
air
vinegar in water
homogenous
heterogenous

28. Identify the following as a homogeneous mixture or heterogenous mixture?
salt water
beef stew
sand and water
soil
homogenous
heterogenous

29. Identify the following as a chemical property or physical property
color
hardness
ability to react
freezing point
physical
chemical

30. Identify the following as a chemical property or physical property
mass
density
ability to rust
melting point
physical
chemical

31. Identify the following as a physical or chemical change
corrosion
melting
food rotting
explosion
chemical
physical

32. Identify the following as a physical or chemical change
toasted bread
evaporating sea water
dissolving sugar in water
chemical
physical

33. Identify the following as a physical or chemical change
gasoline burns
gasoline boils
oxygen is added to gasoline
chemical
physical