Ch 11 Compounds, Mixtures and Solutions

Question 1

what are compounds

Answer 1

substances made by joining together two or more elements

Question 2

what are bonds

Answer 2

strong forces that chemically join together the elements in a compound

Question 3

what is a mixture

Answer 3

a material containing two or more elements or compounds that are in close co tact and are mixed e.g. seawater is a mixture of salts and water

Question 4

what are molecules

Answer 4

groups of two or more atoms bonded together e.g. water and carbon dioxide

Question 5

what is the characteristic of pure substances

Answer 5

they contain only atoms or molecules of that substance e.g. oxygen

Question 6

how do you test the purity of a substance

Answer 6

measure the physical properties: melting point
boiling point
density

Question 7

what is the solute

Answer 7

the substance that dissolves

Question 8

what is the solvent

Answer 8

the substance that the solute dissolved into

Question 9

what is a solution

Answer 9

when a solute dissolves into a solvent it forms a solution

Question 10

what does soluble mean

Answer 10

solids that dissolve are soluble

Question 11

what does insoluble mean

Answer 11

solids that don’t dissolve are insoluble

Question 12

what is suspension

Answer 12

when a solids doesn’t dissolve and settles to the bottom of the liquid or floats around

Question 13

what is solubility

Answer 13

a measure of how much solute can dissolve in a fixed volume of solvent to make a saturated solution

Question 14

what is concentration

Answer 14

how much solute is dissolved in the solvent

Question 15

what is a dilute solution

Answer 15

it contains a small quantity of solute in a large quantity of solvent

Question 16

what is a concentrated solution

Answer 16

it contains a large quantity of solute in a small quantity of solvent

Question 17

what is a saturated solution

Answer 17

it contains as much solute as possible at a given temperature

Question 18

what is crystallization

Answer 18

the formation of crystals ( cooling a saturated solution )

Question 19

in what ways can separation of mixture be done

Answer 19

1. filtration
2. chromatography
3. evaporation
4. distillation
5. magnetism
6. separating immiscible liquids

Question 20

describe the process of filtration

Answer 20

it is used to separate insoluble solids from liquids.

you use filter paper and put the liquid through it. the insoluble solids should get stuck in the paper and the liquid should go through

Question 21

describe chromatography

Answer 21

it is used to separate mixture of substances that are in solution

the different substances are carried up a piece of chromatography paper by the solvent at different rates

Question 22

describe evaporation

Answer 22

it is used to separate a liquid and a soluble solid

the solvent is evaporated and the solute is left behind in the evaporating dish

Question 23

describe distillation

Answer 23

it is used to separate a liquid and a soluble solid when you want to keep the solvent

the liquid with the lowest boiling point evaporated first . a liebig condenser is used during distillation

Question 24

describe magnetism

Answer 24

used to separate if one of the substances in the mixture is magnetic

the substance will be attracted the the magnet

Question 25

explain separating immiscible liquids

Answer 25

the less dense liquid will float on top of the other liquid. a separating funnel can be used to separate immiscible liquids

Question 26

how does fractional distillation

Answer 26

crude oil is separated by fractional distillation the oil is heated and turns to a gas. the gas is out in a large tower and it cools as it rises up the tower. substances with high boiling points turn to liquid at the bottom of the tower and substances with low boiling points turn liquid at the top

Question 27

what are monomers

Answer 27

raw materials separated from crude oil by fractional distillation

Question 28

what is polymerisation

Answer 28

when small repeating units called monomers bond together to form larger chains called polymers

Question 29

what does non- biodegradable mean

Answer 29

bacteria cannot break them down

Question 30

explain the process of fracking

Answer 30

fracking involves drilling into the earth and injecting a mixture of water,sand, and chemicals into the rick at high pressure, which releases the gas trapped in the rock.

Question 31

what are three advantages of fracking

Answer 31

- provides access to oil and gas - releases methane which is the least polluting of all fossil fuels - provides fuel source

Question 32

what are three disadvantages of fracking

Answer 32

- large amount of water are needed - may result in small earthquakes - natural gas is a non renewable form of energy