Topic 9

Question 1

What colour does the flame go if a lithium ion is present?

Answer 1

Red flame

Question 2

What colour does the flame go if a sodium ion present?

Answer 2

Yellow flame

Question 3

What colour does the flame go if potassium ions are present?

Answer 3

Lilac flame

Question 4

What colour does the flame go if calcium ions are present?

Answer 4

Orange-red flame

Question 5

What colour does the flame go if copper ions are present?

Answer 5

Blue-green flame

Question 6

How do you carry out a flame test?

Answer 6

Sterilise a wire loop by dipping it in HCL and rinsing it in distilled water
Dip the wire in a metal compound and put it in the clear blue part of the Bunsen burner
Record the colour of flame

Question 7

How do you carry out the test for metal ions?

Answer 7

Add sodium hydroxide to the compound

Question 8

What is precipitate is produced when an aluminium ion is present?

Answer 8

White at first but then colourless

Question 9

What is precipitate is produced when an calcium ion is present?

Answer 9

White precipitate

Question 10

What is precipitate is produced when a copper ion is present?

Answer 10

Blue precipitate

Question 11

What is precipitate is produced when an iron II ion is present?

Answer 11

Green precipitate

Question 12

What is precipitate is produced when an iron III ion is present?

Answer 12

Brown precipitate

Question 13

What is the test for halide ions?

Answer 13

Adding dilute nitric acid and silver nitrate solution to the halide

Question 14

What colour precipitate does chloride give off?

Answer 14

White precipitate of silver chloride

Question 15

What colour precipitate does bromide give off?

Answer 15

A cream precipitate of sliver bromide

Question 16

What colour precipitate does iodide give off?

Answer 16

A yellow precipitate of sliver iodide

Question 17

what is the test for carbonate ions?

Answer 17

Adding dilute acid to the solution

Question 18

What happens when carbonate ions are present?

Answer 18

The mixture will fizz

Question 19

What is the test for sulfate ions?

Answer 19

Add some hcl to test the sample and add some barium chloride solution

Question 20

What happens when sulfate ions are present?

Answer 20

A white precipitate of barium sulfate will form?

Question 21

What is flame photometry?

Answer 21

An instrumental method that allows us to identify ions in a dilute solution

Question 22

What does the line spectrum show in flame photometry?

Answer 22

The intensity of the measure wavelength indicates the concentration of that ion in solution

Question 23

What are the 3 advantages of using flame photometry?

Answer 23

Very sensitive -detect everything
Very fast
Very accurate

Question 24

What are alkanes?

Answer 24

Saturated hydrocarbons

Question 25

Define a homologous series

Answer 25

A group of chemicals that have similar chemical structures

Question 26

What is the general formula for alkanes

Answer 26

CnH2n+2

Question 27

What are the first 5 alkanes?

Answer 27

``` Methane Ethane Propane Butane Pentane ```

Question 28

What are the chemical formulas for the first 5 alkanes?

Answer 28

``` M- CH4 E- C2H6 P- C3H8 B- C4H10 PE- C5H12 ```

Question 29

What is the general formula for alkenes?

Answer 29

CnH2n

Question 30

Why are alkenes known as unsaturated?

Answer 30

They can make more bonds since it can open up

Question 31

What are the first 3 alkenes?

Answer 31

Ethene Propene Butene

Question 32

How do you test for alkanes and alkenes?

Answer 32

Bromine water

Question 33

What happens when alkanes or alkenes are present in bromine water?

Answer 33

Alkane- stay orange | Alkene- turns it colourless

Question 34

What are polymers?

Answer 34

Substances of high average relative molecular mass made by joining up lots of small repeating units called monomers

Question 35

Define addition polymerisation

Answer 35

Lots of unsaturated monomer molecules which can open up their double bonds and join together to form polymer chains

Question 36

How do you get the formula of a polymer?

Answer 36

Put the formula of the monomer in brackets and put an n after it e.g C3H6 becomes (C3H6)n

Question 37

How do you draw the repeat unit of a polymer?

Answer 37

Break the double bond and join the carbons together in a row Put it in brackets around the repeating but and put an n after it

Question 38

What are the properties of poly(ethene)?

Answer 38

Flexible electrical insulator cheap

Question 39

What are the uses of poly(ethene)?

Answer 39

Plastic bags Bottles Wire insulation

Question 40

What are the properties of poly(propene)?

Answer 40

Flexible Strong Tough Mouldable

Question 41

What are the uses of poly(propene)?

Answer 41

Crates Furniture Ropes

Question 42

What are the properties of poly(chloroethene)?

Answer 42

Tough | Cheap

Question 43

What are the uses of poly(chloroethene)?

Answer 43

Window frames | Water pipes

Question 44

What are the properties of poly(tetrafluoroethene)?

Answer 44

Unreactive Tough Non stick

Question 45

What are the uses of poly(tetrafluoroethene)?

Answer 45

Non stick pans | Waterproof clothing

Question 46

Give a method in which polymers can be made

Answer 46

Condensation polymerisation

Question 47

How does condensation polymerisation occur?

Answer 47

Monomers react together and bonds form between them, making polymer chains

Question 48

What are the problems with disposing of polymers in landfill sites?

Answer 48

Lots of valuable land is used for landfill Most polymers are non-biodegradable Too expensive or difficult

Question 49

What are the problems with disposing of polymers by combustion?

Answer 49

Toxic gas can be released | Co2 is produced