Section 2 - States of Mater & Mixtures

Question 1

What are the three states of matter?

Answer 1

Solid, liquid and gas.

Question 2

In a solid’s particle model, how are the particles arranged?

Answer 2

A regular lattice from which the particles don’t move.

Question 3

What are the properties of solids?

Answer 3

Strong forces of attraction between particles, holding all particles in a fixed lattice arrangement, they keep a definite shape and volume, they don’t have much energy, they expand as they heat up.

Question 4

In a liquid’s particle model, how are the particles arranged?

Answer 4

Some of the particles will be touching one another, but they will be laid out irregularly and spread out.

Question 5

What are the properties of liquids?

Answer 5

Some force of attraction between particles, allowing free movement of particles whilst sticking them together, no definite shape but keep constant volume, some energy, expand when heated.

Question 6

In a gas’s particle model, how are the particles arranged?

Answer 6

Randomly spread out.

Question 7

What are the properties of gases?

Answer 7

No forces of attraction between particles, allowing free movement of particles, no definite shape or volume, have lots of energy, move randomly, expand when heated or under pressure.

Question 8

When a solid turns to a liquid, what is it called?

Answer 8

Melting.

Question 9

When a liquid turns to a solid, what is it called?

Answer 9

Freezing.

Question 10

When a liquid turns to a gas, what is it called?

Answer 10

Evaporating.

Question 11

When a gas turns to a liquid, what is it called?

Answer 11

Condensing.

Question 12

When a solid turns to a gas, or a gas turns to a solid, what is it called?

Answer 12

Subliming.

Question 13

What are physical changes?

Answer 13

Changes in state.

Question 14

What are chemical changes?

Answer 14

Rearrangements of atoms in compounds due to chemical reactions.

Question 15

Compared to physical changes, how hard are chemical changes to reverse?

Answer 15

Harder.

Question 16

What is pure in chemistry?

Answer 16

Pure means only made of one element or compound.

Question 17

How can you test a solid’s purity with heat?

Answer 17

By melting it and comparing it’s melting point to it’s pure melting point.

Question 18

What is distillation?

Answer 18

A separation technique to separate mixtures containing liquids.

Question 19

How does distillation work?

Answer 19

The liquids evaporate at different temperature, this allows the liquids with lower boiling points to boil out of the mixture, separating it from the other chemicals.

Question 20

What are the two types of distillation?

Answer 20

Simple and fractional.

Question 21

What is filtration used for?

Answer 21

To separate an insoluble solid from a liquid.

Question 22

What is crystalisation used for?

Answer 22

To separate soluble solids from a mixture.

Question 23

What is chromatography?

Answer 23

A method to separate a mixture of soluble substances and identify them.

Question 24

What are the two phases of chromatography?

Answer 24

Mobile and stationary.

Question 25

What is the mobile phase in chromatography?

Answer 25

Where the molecules can move, this is either a liquid or a gas.

Question 26

What is the stationary phase in chromatography?

Answer 26

Where the molecules can't move, this is either a solid or a really thick liquid.

Question 27

What is the R(v)f value? What does it stand for?

Answer 27

The ratio between the distance traveled by the solute and the distance traveled by the solvent, it stands for retardation factor.

Question 28

How can you test purity with chromatography?

Answer 28

A pure substance forms a blob and won't be separated, unlike a mixture.

Question 29

What are the three types of water source we use to provide us with drinking water.

Answer 29

Surface water, ground water and waste water.

Question 30

What is surface water?

Answer 30

Water from lakes, rivers and reservoirs.

Question 31

What is ground water?

Answer 31

Water from aquifers.

Question 32

What is waste water?

Answer 32

Water that has been contaminated by some human process.

Question 33

What is an aquifer?

Answer 33

Any type of rock that traps water underground.

Question 34

Which types of water source require treatment before use?

Answer 34

Waste water and surface water.

Question 35

What does potable mean, in relation to water?

Answer 35

It means the water is fit to drink.

Question 36

What three stages does water go through in water treatment?

Answer 36

Filtration, sedimentation and chlorination.

Question 37

How does filtration work in water treatment?

Answer 37

A large wire mesh is used to remove twigs and the like before a sand and gravel bed filter out other solids.

Question 38

How does sedimentation work in water treatment?

Answer 38

Either iron sulfate or aluminium sulfate is added to the water to cause fine particles to clump up and settle at the bottom of the tank.

Question 39

How does chlorination work in water treatment?

Answer 39

Chlorine gas is bubbled through the water to kill of harmful bacteria and other microbes.

Question 40

What water source could be used in dry countries near the ocean? how would it be made drinkable?

Answer 40

Sea water, distillation would purify the water.

Question 41

What are the disadvantages of using distillation over other water treatment methods?

Answer 41

It is uses large amounts of energy and is very expensive.

Question 42

Why must water used in chemical analysis be pure?

Answer 42

It would contaminate the result otherwise.