Unit 4.01 - 4.03

Question 1

What can we consider when physical state of matter is altered?

Answer 1

The change is considered to be physical change, but the chemical properties remains the same.

Question 2

Solid –> Liquid

Answer 2

Melting
- IMF weakened; energy absorbed

Question 3

Liquid –> Gas

Answer 3

Boiling
-IMF broken; energy absorbed

Question 4

Gas -> Liquid

Answer 4

Condensing
-IMF formed; energy released

Question 5

Solid –> Gas

Answer 5

Sublimation
- IMF broken; energy absorbed

Question 6

Gas –> Solid

Answer 6

Reverse sublimation or deposition
- IMF formed; energy released

Question 7

Liquid –> Solid

Answer 7

Freezing
- IMF formed; energy released

Question 8

In order to weaken bonds, is energy absorbed or released?

Answer 8

absorbed

Question 9

In order to strengthen bonds, is energy absorbed or released?

Answer 9

released

Question 10

Water can have a lower boiling point when….

Answer 10

pressure decreases.

Question 11

What stays the same when a matter skips a phase when transforming?
Example: Solid –> Gas

Answer 11

The amount of energy stays the same

Question 12

What happens to the particles when a solid is heated?

Answer 12

The particles gain energy, move around more, and eventually gain enough energy to break away from their fixed positions, break intermolecular forces, and for a liquid

Question 13

What does continued heating lead to?

Answer 13

Leads to the liquid particles gaining sufficient energy and forms into a gas.

Question 14

Define chemical reactions

Answer 14

When the atoms of a substance are rearranged to form a new substance

Question 15

What are “Driving Forces” and what are examples of it?

Answer 15

Driving Forces are observable changes that often accompany chemical reactions
- A precipitate forms
- A change of energy in the form of heat or light
- Observe a color change (sometimes; has to be a permanent change)
- See the formation of a gas
- Observe electrical current (a flow of electrons)

Question 16

How can you tell the difference between a chemical and physical change?

Answer 16

• If a new product forms, it’s a chemical change
• If chemical bonds are broken or made, it’s a chemical change
• If intermolecular forces are broken or made, it’s a physical change

Question 17

Evaporation is a ________ process

Answer 17

cooling

Question 18

Boiling is a _________

Answer 18

process

Question 19

Explain the magnificent seven

Answer 19

The magnificent seven are diatomic elements that always appear in groups of 2 when they are alone.
Example: H2, N2, O2, F2, Cl2, Br2, I2

Question 20

What must you do when balancing equations?

Answer 20

Only place numbers in front of the whole formula. Do not the change the “correct) formula of any of the reactants or products, or add extra formulas.

Question 21

Define aqueous

Answer 21

Meaning in solution with water as the solvent

Question 22

What are often carried out in aqueous solutions?

Answer 22

Many qualitative (quality; described in words) and quantitative (numbers) chemical reactions

Question 23

What are electrolytes?

Answer 23

Ions in water

Question 24

Define strong electrolytes

Answer 24

A large number of ions are present in a solution
- Breaks away completely

Question 25

What are the strong electrolytes?

Answer 25

Na+, K+, NH4+, and NO3-

Question 26

What are weak electrolytes?

Answer 26

When a solution is likely to have only a few ions where only some of these ions break away.

Question 27

Define non-electrolytes

Answer 27

Non0electrolytes still dissolve but don’t form ions. Usually polar covalent bods are non-electrolytes

Question 28

What do strong electrolytes appear as in net-ionic equations?

Answer 28

Only ions as the reactant and product

Question 29

What do weak electrolytes appear as in net-ionic equations?

Answer 29

As the molecule as a reactant and ions as a product

Question 30

What do non-electrolytes appear as in net-ionic equations?

Answer 30

As molecules as reactant and product (no ions)

Question 31

What can ionic equations be used for?

Answer 31

To see the degree of ionization taking place

Question 32

No matter how the chemical or physical process is represented in an equations, it can be ____________________

Answer 32

… translated into a particulate diagram where symbols can be used to represent the equation.

Question 33

What is important to consider when it comes to all particles being present in a reaction?

Answer 33

Important to consider the conservation of mass and conservation of charge that all of the particles that were present at the start of the reaction are present at the end as well

Question 34

How do you draw particle diagrams?

Answer 34

1. You need to start and end with the same number and types of atoms/ions unless a gas is formed and leaves the open container.
2. If ionic make sure the particles match the charge of ions.
3. The overall charge should equal zero.
4. Count the particles to make sure the answer makes sense