Review

Question 1

How is matter classified?

Answer 1

Matter can be classified as a pure substance or a mixture

Question 2

What is the difference between a homogenous and heterogeneous mixture?

Answer 2

In a heterogenus mixture the parts that are in it can be easily distinguished while in a homogenous mixture the substances mix together to make it look uniform or as one.

Question 3

What is a suspension? (chemically)

Answer 3

A heterogeneous mixture in which particles settle slowly and are large enough to be trapped by a filter

Question 4

What is a colloid?

Answer 4

A heterogeneous mixture with particles that are larger than those of the solution, and cannot settle

Question 5

What is an emulsion?

Answer 5

An emulsion is to disperse particles for a larger period of time in a colloid e.g. Mayo * a emulsifying agent must be added

Question 6

The particle Model of Matter

Answer 6

1. All matter is made of particles 2. The particles are always moving 3. They have space between them 4. Move faster once heat is added 5. Are attracted to each other

Question 7

What properties distinguish solids, gases, and liquids

Answer 7

Shape and volume, movement, compressibility, space, flow

Question 8

Action of particles in a solid

Answer 8

Shape and volume: fixed shape and volume Movement: rigid-vibrating Compressibility: Not easily Space: Very little space Flow: Form pile when poured

Question 9

Action of particles in a liquid

Answer 9

Shape and volume: takes shape of container Movement: can slide past molecules Compressibility: Not easily
Space: Little space
Flow: can be pored and create a flat surface, and flows to lowest level

Question 10

Action of particles in a gas

Answer 10

Shape and volume: assume the shape and volume of the container
Movement: molecules can move past one another
Compressibility: Compressable
Space: Lots of free space
Flow: flow easily past each other in all directions to the higher level

Question 11

Describe the Changes of State and the terminology used, when a substance undergoes a specific change of state.

Answer 11

Solid-Liquid: Melting
Liquid-Gas: Evaporating
Gas-Solid: Sublimation
Solid-Gas: Sublimation
Gas-Liquid: Condensation
Liquid-Solid: Freezing

Question 12

What conditions must be present to enable a material to dissolve
in another material?

Answer 12

One of the materials must be a solvent while the other should be a solute that is soluble in that solvent, and have the right temperature

Question 13

Explain the difference between a solute and a solvent

Answer 13

The solvent is the substance in a solution that does the dissolving, while the solute is the substance in the solution that is dissolving.

Question 14

Why is water called “the universal solvent”

Answer 14

This is because it dissolves more solutes than other solvents in the world

Question 15

What affects the rate at which a material will dissolve

Answer 15

The temperature, type of solute and solvent, if it is being stirred or shaken, the amount of solute or solvent, all change the rate a material will dissolve.

Question 16

What is a saturated solution

Answer 16

A solution where there is no room for any more solute to dissolve

Question 17

Why are some substances insoluble

Answer 17

This is because the particles don’t attract other types of particles

Question 18

Describe various methods by which mixtures may be separated and
provides examples of mixtures that may be separated by each
method

Answer 18

Distillation, fractional distillation, desalination, and chromatography. Distillation is used to recover the solvent from the solution e.g. water from saltwater. Fractional distillation is used to separate two different liquids with different boiling points e.g. crude oil. Desalination is used only for separating impurities such as salt, from the water only. Chromatography is used to separate substances with different colors e.g. ink.

Question 19

Describe the ‘desert tent’ method of separation

Answer 19

The “desert tent” method of separation refers to desalination, where a pot with impurified water sits underneath a cover of plastic a few inches above, and when the sun heats up the water, it evaporated and catches onto the plastic where it then condenses then pools in the containers on each side of the plastic.

Question 20

What is desalination

Answer 20

Desalination is a method for seprating salt and other impurities from slatwater so that you are left with dirinkable water

Question 21

Describe how distillation is able to separate the parts of a solution

Answer 21

First in a container, the solution is heated up until it evaporates, and the solute is left behind since most of the time, it has a lower boiling point. As the evaporated solvent goes through the cooling tubes, it condenses and pools inside the other container.

Question 22

How is petroleum separated and the fractional parts collected

Answer 22

This is done through fractional distillation, since the different liquids in crude oil have different boiling points. Each section is heated to a certain temperature in which only one of the liquids evaporate, and they go through a tube and then is collected.

Question 23

How is ore (such as gold) mined and collected

Answer 23

smelting which is the process of heating the ore and adding a reducing agent

Question 24

solid
liquid
gas
pure substance
properties
mixture
homogeneous
solution
heterogeneous
suspension
colliod
emulsion
mechanical mixture
phases
dissolving
solute
solvent
soluble
rate of dissolving
agitation
saturated solution
unsaturated solution
supersaturated solution
insoluble

Answer 24

Solid- a state of matter which has a definite shape and volume
Liquid- a state of matter neither gas or solid
Gas- state of matter with no definite shape
Pure substance- type of matter with a fixed composition and can’t be separated by physical means
Properties-characteristics of a substance such as color, hardness, and odor
Mixture- material made up of 2 or more substances
Homogenous- types of mixture in which the substances look uniform or as one
Solution- a homogenous mixture, where there is no settling of its substances
Heterogenous- type of mixture which is made up of parts that can be easily distinguished
Suspension- a heterogeneous mixture where the particles settle slowly and are bid enough to be caught with a filter
Colloid- a heterogeneous mixture in which the particles do not settle and are larger than those of the solution
Emulsion- the process of dispersing particles in colloid for a larger period of time using an emulsifying agent
Mechanical Mixture- an obvious heterogenous mixture made up of two or more mixtures
Phases- the parts of a mechanical mixture
Dissolving- when the solute of a solution is incorperated with a solvent to create a solution
Solute- the substance in a solution that dissolves
Solvent- the substance in a solution that does the dissolving
Rate of dissolving- how long it take for a solute to dissolve into a solution
Agitation- to stir of shake a mixture
Saturated-A solution where there is no room for any more solute to dissolve
Unsaturated- a solution in which there is still more room for more solute
Supersaturated-A solution that holds more solute than it would normally be able to dissolve at a certain temperature
Insoluble- when a solute is unable to dissolve into a solvent