Classification of Substances Unit Test

Question 1

Define a mixture.

Answer 1

Two or more chemical components that are mixed together, but are NOT chemically bound.

Question 2

Define a compound.

Answer 2

Two or more chemical components that ARE chemically bound.

Question 3

Define an element.

Answer 3

A single component that cannot be divided into various types of substances. OR A pure substance.

Question 4

Define a mechanical mixture.

Answer 4

Two or more components that can be seen as different and are not chemically bound.

Question 5

Is cobalt (Co) a mixture, compound or element?

Answer 5

Element.

Question 6

Is a smoothie a mixture, compound or element?

Answer 6

Mixture.

Question 7

Is clean air a mixture, compound or element?

Answer 7

Mixture.

Question 8

Is copper chloride (CuCl2) a mixture, compound or element?

Answer 8

Compound.

Question 9

Is a block of lead a mixture, compound or element?

Answer 9

Element.

Question 10

Your car windshield begins to fog up. What is change between physical states is occurring?

Answer 10

Condensation (gas to liquid).

Question 11

What is the change between physical states that occurs with dry ice?

Answer 11

Sublimation (solid to gas).

Question 12

Your kettle emits steam as the water boils. What is the change between physical states that is occurring?

Answer 12

Evaporation (liquid to gas).

Question 13

A stick of butter is placed in a hot frying pan. What is the change between physical states that is about to occur?

Answer 13

Melting (solid to liquid).

Question 14

Frost has gathered on the windows. What change in physical states took place?

Answer 14

Deposition (gas to solid).

Question 15

A tray of ice cubes hardens in the freezer. What is this change in physical state?

Answer 15

Freezing (liquid to solid).

Question 16

Define an extensive property.

Answer 16

An extensive property varies with the amount of a substance (mass, volume, weight).

Question 17

Define an intensive property.

Answer 17

An intensive property does not change no matter the amount of a substance (colour, melting point, boiling point, conductivity, physical state).

Question 18

Extensive or intensive property: Water begins to boil at 100 degrees Celsius.

Answer 18

Intensive.

Question 19

Extensive or intensive property: You have 2.3 grams of nutrient agar in a weigh boat.

Answer 19

Extensive.

Question 20

Extensive or intensive property: A red rock.

Answer 20

Intensive.

Question 21

Extensive or intensive property. Copper conducts electricity.

Answer 21

Intensive.

Question 22

Extensive or intensive property. A piece of wood has a volume of 7 cubic meters.

Answer 22

Extensive.

Question 23

What separation technique would you use for a solid in a solid?

Answer 23

Hand separation (using a sieve or a magnet).

Question 24

What separation technique would you use for a solid in a liquid when you want the solid in a pure crystalline state and not the liquid?

Answer 24

Recrystallization.

Question 25

What separation technique would you use if you want a solid but not the liquid?

Answer 25

Evaporation.

Question 26

What separation technique would you use for a liquid in a liquid?

Answer 26

Distillation.

Question 27

What separation technique would you use to dissolve one component of a solid in solid mixture?

Answer 27

Solvent extraction.

Question 28

What separation technique would you use to separate a mechanical mixture based upon density?

Answer 28

Gravity separation.

Question 29

What separation technique would you use for a solid in liquid solution when you want small amounts of the solid?

Answer 29

Chromatography.

Question 30

What separation technique would you use for a solid in a liquid mechanical mixture?

Answer 30

Filtration.

Question 31

Define an atom.

Answer 31

A single neutral particle.

Question 32

Define a molecule.

Answer 32

Neutral particles made of two or more atoms bound together.

Question 33

Define an ion.

Answer 33

A negative or positively charged particle.

Question 34

What is a chemical change?

Answer 34

A change occurs and a new product is created. OR Atoms rearrange themselves.

Question 35

What is a physical change?

Answer 35

A change occurs, but NO new product is created. OR Atoms may speed up, slow down, be heated or cooled.

Question 36

Define a heterogeneous mixture.

Answer 36

All the components of the mixture do not mix uniformly (for example, stew).

Question 37

Define a homogeneous mixture.

Answer 37

All components are uniformly mixed.

Question 38

Gas to solid.

Answer 38

Deposition.

Question 39

Solid to gas.

Answer 39

Sublimation

Question 40

Gas to liquid.

Answer 40

Condensation.

Question 41

Solid to liquid.

Answer 41

Melting.

Question 42

Liquid to solid.

Answer 42

Freezing.

Question 43

Liquid to gas.

Answer 43

Evaporation.

Question 44

Chemical or physical change? Expansion of a solid when heated.

Answer 44

Physical change.

Question 45

Chemical or physical change? Food rotting.

Answer 45

Chemical change.