A: Chemistry = Chemical Changes 1.4 Solutions and Concentrations

Question 1

What is a solution?

Answer 1

A solute dissolved in a solvent.

Question 2

What are some common examples of commercial solutions?

Answer 2

• Beverages
• Medicines
• Household cleaners
• Hair-care products

Question 3

What can changing the ratio of solute to solvent in a solution do?

Answer 3

Dramatically change the properties of the solution.

Question 4

What is the concentration of acetic acid in vinegar commonly used in cooking?

Answer 4

5% solution of acetic acid.

Question 5

True or False: A concentrated solution of acetic acid is safe for consumption.

Answer 5

False.

Question 6

Why are there regulations about the proper labeling of products?

Answer 6

To keep consumers safe.

Question 7

Fill in the blank: The ratio of solute to solvent is often noted on the product’s _______.

Answer 7

label.

Question 8

What are polychlorinated biphenyls (PCBs)?

Answer 8

PCBs are pollutants that can be present in water and fish.

Question 9

Where can PCBs be found?

Answer 9

In water and fish living in water polluted with PCBs.

Question 10

What is the maximum concentration of PCBs allowed in fish according to Canada’s health guidelines?

Answer 10

2 parts per million (ppm).

Question 11

What is the purpose of the PCB concentration guideline in fish?

Answer 11

To ensure that the fish you eat will not harm you.

Question 12

Fill in the blank: The maximum concentration allowed by Canada’s health guidelines regarding the level of PCBs in fish is _______.

Answer 12

2 parts per million (ppm).

Question 13

What is the definition of concentration in a solution?

Answer 13

The ratio of the quantity of solute to the quantity of solution

Concentration describes how much solute is present in a given volume of solution.

Question 14

What is a concentrated solution?

Answer 14

A solution containing a high ratio of solute to solution

Concentrated solutions have more solute compared to the volume of solvent.

Question 15

What is a dilute solution?

Answer 15

A solution containing a low ratio of solute to solution

Dilute solutions have less solute in a given volume of solvent.

Question 16

True or False: A solution with more solute than another solution of the same volume is considered more concentrated.

Answer 16

True

This indicates that the amount of solute is greater in comparison to the solvent.

Question 17

What is the concept of concentration?

Answer 17

A measure of how much solute is present in a solution or mixture

Concentration is encountered in everyday situations such as buying products or assessing water quality.

Question 18

Why is understanding concentration important?

Answer 18

It helps answer questions about solute amounts, safety limits, safety concerns, and cost-effective product purchasing

Understanding concentration aids in interpreting product information and making informed decisions.

Question 19

Fill in the blank: Concentration is important for determining _______.

Answer 19

[solute amounts]

Question 20

What types of questions can understanding concentration help you explore?

Answer 20

It helps explore questions about:
* Solute amounts in products
* Safe limits for chemicals
* Safety concerns with high concentrations
* Cost savings from buying concentrated solutions

These questions are relevant in both daily life and scientific contexts.

Question 21

True or False: Concentration is only relevant in scientific contexts.

Answer 21

False

Concentration is relevant in everyday activities such as shopping and health assessments.

Question 22

What are qualitative properties of solutions?

Answer 22

Qualitative properties of solutions are characteristics that can be observed without measuring quantities, such as colour, taste, and odour.

Question 23

How can you distinguish between concentrated and dilute juice?

Answer 23

You can distinguish between concentrated and dilute juice by tasting, observing differences in colour, and noticing consistency.

Question 24

Fill in the blank: You can get a lot of information about a substance simply by observing its _______.

Answer 24

physical properties

Question 25

True or False: Qualitative properties require quantitative measurements to be understood.

Answer 25

False

Question 26

List some examples of qualitative properties.

Answer 26

* Colour * Taste * Odour

Question 27

What is one method to compare the concentration of two solutions?

Answer 27

Compare how the two different solutions conduct electricity ## Footnote This involves placing two electrodes into a solution and measuring the ease of electrical current passage.

Question 28

How does the concentration of a solution affect its ability to conduct electricity?

Answer 28

Solutions with higher concentrations are more effective at passing current than dilute solutions ## Footnote Higher concentration solutions have more ions available to carry the electrical charge.

Question 29

Fill in the blank: Solutions with higher concentrations are ______ than dilute solutions at passing the current.

Answer 29

more effective

Question 30

What equipment can be used to measure the conductivity of a solution?

Answer 30

Two electrodes

Question 31

True or False: It is always easy to tell which solution has a higher concentration by looking at it.

Answer 31

False

Question 32

What theory explains that a chemical reaction will occur if particles collide with a certain minimum energy and orientation?

Answer 32

collision-reaction theory ## Footnote This theory states that collisions between atoms, ions, and molecules are essential for chemical reactions.

Question 33

What is required for a chemical reaction to occur according to the collision-reaction theory?

Answer 33

Particles must collide with a certain minimum energy and orientation ## Footnote The correct energy and orientation ensure that a chemical reaction can take place.

Question 34

What happens to particles after they collide in a chemical reaction?

Answer 34

They undergo rearrangement ## Footnote This rearrangement of particles leads to the formation of new substances.

Question 35

True or False: All chemical reactions involve collisions between atoms, ions, and molecules.

Answer 35

True ## Footnote Collisions are a fundamental aspect of chemical reactions as per the collision-reaction theory.

Question 36

Fill in the blank: The __________ theory states that chemical reactions involve the collision and rearrangement of particles.

Answer 36

collision-reaction ## Footnote This theory is crucial for understanding the dynamics of chemical reactions.

Question 37

What affects the speed of chemical reactions?

Answer 37

Concentration of solute in a solution

Question 38

How does a concentrated solution compare to a dilute solution in terms of particle availability?

Answer 38

A concentrated solution has more particles of solute available for possible collisions

Question 39

What is the relationship between the number of solute particles and the probability of collisions?

Answer 39

The probability of collisions increases as the number of solute particles within a system increases

Question 40

Reactions with concentrated solutions occur _______ compared to dilute solutions.

Answer 40

more quickly

Question 41

True or False: Reactions with dilute solutions occur at a faster rate than reactions with concentrated solutions.

Answer 41

False

Question 42

What is a key reason that reactions with dilute solutions occur at a slower rate?

Answer 42

Collisions are less probable

Question 43

What affects the speed of chemical reactions?

Answer 43

Concentration of solute in a solution

Question 44

How does a concentrated solution compare to a dilute solution in terms of particle availability?

Answer 44

A concentrated solution has more particles of solute available for possible collisions

Question 45

What is the relationship between the number of solute particles and the probability of collisions?

Answer 45

The probability of collisions increases as the number of solute particles within a system increases

Question 46

Reactions with concentrated solutions occur _______ compared to dilute solutions.

Answer 46

more quickly

Question 47

True or False: Reactions with dilute solutions occur at a faster rate than reactions with concentrated solutions.

Answer 47

False

Question 48

What is a key reason that reactions with dilute solutions occur at a slower rate?

Answer 48

Collisions are less probable