unit 2 test review. when an iron nail is ground into powder what happens to it’s mass? it stays...

Unit 2 Test Review

When an iron nail is ground into powder what happens to it’s mass?

It stays the same

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.

A sample of gas occupies 17 mL at –112o C What volume does the sample occupy at 70o C?

= 36 mL17 mL X 343 K 161 K

What would happen to the pressure with the following change?

The temperature is increased.

Pressure increases

What would happen to the pressure with the following change?

The volume of the container is increased.

Pressure decreases

What would happen to the pressure with the following change?

More of the gas is added to the container.

Pressure increases

What would happen to the pressure with the following change?The average kinetic energy of the gas

in increased.

Pressure increases

What method would you use to determine the average kinetic energy of the molecules of water in a glass.?

measure the water’s temperature

Describe the movement of ideal gases according to the kinetic theory

Motion is constant, random, and rapid

During which intervals on the graph is the average kinetic energy of the molecules in the sample decreasing?

20-kg sample of a substance as it is cooled at a constant rate

A, C and E

How can you be CERTAIN that a chemical change has taken place?

Check the composition of the sample before and after the change.

What distinguishes a substance from a mixture?

Mixtures can be separated physically, while compounds cannot

Standard conditions when working with gases are defined as ____.

0o C and 101.3 kPa

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

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

Explain equilibrium vapor pressure.

In a closed container the rate of evaporation will equal the rate of condensation

As the temperature of the gas in a balloon decreases, what happens to each of the following?

volume

pressure

kinetic energy

decreases

decreases

decreases

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

liquid

Which state of matter is most dense?

solids

Which state of matter have the strongest intermolecular attractions

solids

Which state of matter has the most space between their particles

gas

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

gas

Describe an ideal gas

Small particles with no volumes or intermolecular attractions

Classify the following:.

table salt

air

nitrogen

gold

substance /compound

mixture / homogenous

substance / element

substance / element

Classify the following:.

water

stainless steel

noodle soup

oxygen

substance /compound

mixture / homogenous

mixture / heterogenous

substance / element

Identify the following as a homogeneous mixture or heterogenous mixture?

milk

oil and vinegar

air

vinegar in water

homogenous

heterogenous

homogenous

homogenous

Identify the following as a homogeneous mixture or heterogenous mixture?

salt water

beef stew

sand and water

soil

homogenous

heterogenous

heterogenous

heterogenous

Identify the following as a chemical property or physical property

color

hardness

ability to react

freezing point

physical

physical

chemical

physical

Identify the following as a chemical property or physical property

mass

density

ability to rust

melting point

physical

physical

chemical

physical

Identify the following as a physical or chemical change

corrosion

melting

food rotting

explosion

chemical

physical

chemical

chemical

Identify the following as a physical or chemical change

toasted bread

evaporating sea water

dissolving sugar in water

chemical

physical

physical

Identify the following as a physical or chemical change

gasoline burns

gasoline boils

oxygen is added to gasoline

chemical

physical

physical