topic 1: States of Matter

Question 1

What are the three states of matter?

Answer 1

• Solid
• Liquid
• Gas

Question 2

What is it called when liquids become gas?

Answer 2

• Boiling - Occurs at the boiling point, affects the whole liquid, happens quickly
• Evaporation - Occurs throughout a range of temperatures (though a higher temperature results in a faster rate of evaporation), affects only the surface of the liquid, happens very slowly

This interconversion has two types, although boiling is more important

Question 3

What is it called when solids become liquids?

Answer 3

Melting

All of these interconversions are physical changes, which are easy to reverse and involve no chemical change. They involve the forces between the particles

Question 4

What is it called when gas becomes liquid?

Answer 4

Condensation

Question 5

What is it called when liquids become solids?

Answer 5

Freezing

Question 6

What is it called when a solid becomes a gas?

Answer 6

Sublimation

Question 7

What is it called when a gas becomes a solid?

Answer 7

Deposition

Question 8

What is the change in energy to the particles in melting and evaporating?

Answer 8

The particles gain kinetic energy

Question 9

What is the change in energy to the particles in condensation and freezing?

Answer 9

The particles lose kinetic energy (exothermic)

Question 10

What is the change in arrangement to the particles in condensation and freezing?

Answer 10

It becomes more regular and the particles move closer together

Question 11

What is the change in arrangement to the particles in melting and evaporating?

Answer 11

It becomes more random and the particles move further apart

Question 12

What is a solvent?

Answer 12

The liquid which dissolves the solute

Question 13

What is a solute?

Answer 13

The substance which dissolves in the solvent to form the solution

Question 14

What is a solution?

Answer 14

The substance formed when the solute is dissolved by the solvent

Question 15

What is a saturated solution?

Answer 15

A solution with the maximum possible amount of solute dissolved in it given a fixed volume of solvent

Any more solute added will not be dissolved by the solute and will most likely sink

Question 16

What is the difference between a soluble and an insoluble substance?

Answer 16

• A soluble substance acts as the solute and is able to be dissolved by the solvent
• An insoluble substance cannot be dissolved by the solvent

Question 17

In what units can the solubility of a solute be expressed?

Answer 17

In g per 100 g of solvent

This means the maximum mass of a solute able to be dissolved in 100g of the solvent before it becomes a saturated solution

Question 18

How does the solubility of solids change with temperature?

Answer 18

As temperature increases, solubility increases

Keep in mind these rules are general and some may not increase much at all

Question 19

How does the solubility of gases change with temperature?

Answer 19

As temperature increases, solubility decreases

Question 20

How does the solubility of gases change with pressure?

Answer 20

As pressure increases, solubility increases

Question 21

How do you calculate the mass of solute crystals formed if a solution is cooled?

Answer 21

• Find the solubility at each of the temperatures
• Find the difference between these two values
• Adjust for the volume of the solution

Question 22

Saturated Solution

Answer 22

A solution where the maximum amount of solute has been dissolved in the solvent

Question 23

Solubility

Answer 23

The mass of solute which must dissolve in 100g of solvent to form a saturated solution at a particular temperature.

Question 24

Solute

Answer 24

Substance that dissolves

Question 25

Solution

Answer 25

Mixture formed when a solute dissolves in a solvent

Question 26

Solvent

Answer 26

Liquid that a solute dissolves in

Question 27

describe the structure of a solid

Answer 27

- a regular lattice made up of strong forces of attractions between particles - fixed shape and volume - vibrate around their positions (more heat = more vibrations) - expands slightly when heated

Question 28

Describe the structure of liquids

Answer 28

- a weak force of attraction between particles - fixed volume - doesn't have a fixed shape - particles are randomly arranged and free to move past each other - more heat = faster movement and the heat is used to break the bonds between the particles - expands slightly when heated

Question 29

describe the structure of gases

Answer 29

- very weak forces of attractions between particles - free to move and are far apart - don't have fixed shapes or volumes so they can fill any container - move with random motion in straight lines - more heat = move faster - they can either expand with heat or pressure in a fixed volume will increase

Question 30

what colour is potassium manganate?

Answer 30

purple

Question 31

describe the potassium manganate experiment

Answer 31

purple potassium manganate(solid) is placed in a beaker with some water. over time the potassium manganate will dissolve into the solution turning the solution purple.

Question 32

label this glass tube and explain why the white ring is positioned closer to the left side of the tube

Answer 32

cotton wool soaked in HCL (Left side) cotton wool soaked in aqueous ammonia (right side) ring of ammonium chloride (left centre) the white ring forms closer to the HCL because the ammonia is less dense meaning it can diffuse faster and then react with the HCL sooner.

Question 33

describe the bromine gas experiment

Answer 33

bromine gas is brown place it in an empty beaker and turn the beaker upside down on top of a beaker full of air and separate the two using a glass plate. remove the plate and observe the bromine gas diffusing with the air forming a more dilute brown colour.

Question 34

state the equation to calculate solubility

Answer 34

solubility = mass of solid/mass of water removed x 100