Chapitre 2

Question 1

What is a physical change?

Answer 1

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Question 2

What is a chemical change?

Answer 2

A chemical change is a change that results in the formation of new chemical substances.

Question 3

True or False: During a physical change, the chemical composition of a substance remains the same.

Answer 3

True

Question 4

What principle states that matter cannot be created or destroyed?

Answer 4

The Law of Conservation of Mass

Question 5

Fill in the blank: In a chemical reaction, the total mass of the reactants __________ the total mass of the products.

Answer 5

equals

Question 6

What is a mixture?

Answer 6

A mixture is a combination of two or more substances that retain their individual properties.

Question 7

What is a solution?

Answer 7

A solution is a homogeneous mixture where one substance is dissolved in another.

Question 8

Identify the type of mixture: salad.

Answer 8

Heterogeneous mixture

Question 9

Identify the type of mixture: saltwater.

Answer 9

Homogeneous mixture

Question 10

True or False: All solutions are mixtures, but not all mixtures are solutions.

Answer 10

True

Question 11

What is solubility?

Answer 11

Solubility is the ability of a substance to dissolve in a solvent at a given temperature and pressure.

Question 12

What is the solvent in a solution?

Answer 12

The solvent is the substance that dissolves the solute, typically present in the largest amount.

Question 13

What is the solute in a solution?

Answer 13

The solute is the substance that is dissolved in the solvent.

Question 14

True or False: A saturated solution contains more solute than can be dissolved at a given temperature.

Answer 14

True

Question 15

What happens to the particles in a substance during a physical change?

Answer 15

The particles may rearrange, but their chemical structure remains unchanged.

Question 16

What is an example of a chemical change?

Answer 16

Burning wood or rusting iron.

Question 17

Fill in the blank: A __________ is a physical property that describes how a substance changes when it reacts chemically.

Answer 17

chemical property

Question 18

What does the term ‘homogeneous’ mean in relation to mixtures?

Answer 18

Homogeneous means that the mixture has a uniform composition and appearance throughout.

Question 19

What does the term ‘heterogeneous’ mean in relation to mixtures?

Answer 19

Heterogeneous means that the mixture consists of different components that can be easily distinguished.

Question 20

What is an example of a physical change?

Answer 20

Melting ice or boiling water.

Question 21

What is distillation?

Answer 21

Distillation is a process used to separate components of a mixture based on differences in boiling points.

Question 22

What is filtration?

Answer 22

Filtration is a method used to separate solids from liquids or gases using a filter medium that allows only the fluid to pass through.

Question 23

True or False: The Law of Conservation of Mass applies only to chemical changes.

Answer 23

False

Question 24

What is an example of a colloid?

Answer 24

Milk or fog.

Question 25

What is the role of temperature in solubility?

Answer 25

Generally, increasing temperature increases the solubility of solids in liquids.

Question 26

What is a suspension?

Answer 26

A suspension is a heterogeneous mixture in which solid particles are dispersed in a liquid or gas but will settle over time.

Question 27

What is the process of dissolving?

Answer 27

The process of dissolving is when solute particles are surrounded by solvent molecules and separated from each other.

Question 28

What does it mean for a solution to be concentrated?

Answer 28

A concentrated solution contains a large amount of solute relative to the amount of solvent.

Question 29

What is the difference between a saturated and an unsaturated solution?

Answer 29

A saturated solution contains the maximum amount of solute that can dissolve, while an unsaturated solution can still dissolve more solute.

Question 30

True or False: Chemical changes are usually reversible.

Answer 30

False

Question 31

What is an acid-base reaction?

Answer 31

An acid-base reaction is a chemical reaction that occurs between an acid and a base, resulting in the formation of water and a salt.

Question 32

What is the significance of balancing chemical equations?

Answer 32

Balancing chemical equations ensures that the Law of Conservation of Mass is upheld, with the same number of each type of atom on both sides of the equation.