separate chemistry 2

Question 1

what colour flame does lithium give in the flame test

Answer 1

red

Question 2

what colour flame does sodium give in the flame test

Answer 2

yellow

Question 3

what colour flame does potassium give in the flame test

Answer 3

lilac

Question 4

what colour flame does calcium give in the flame test

Answer 4

orange-red

Question 5

what colour flame does copper give in the flame test

Answer 5

blue-green

Question 6

how do you test for cations

Answer 6

react it with sodium hydroxide

Question 7

what colour precipitate does iron(ll) give in the cation test

Answer 7

green

Question 8

what colour precipitate does iron(lll) give in the cation test

Answer 8

brown

Question 9

what colour precipitate does copper give in the cation test

Answer 9

blue

Question 10

what colour precipitate does calcium give in the cation test

Answer 10

white

Question 11

what colour precipitate does aluminium give in the cation test

Answer 11

white at first but if excess NaOH is added, it is colourless

Question 12

how do you test for ammonia gas

Answer 12

hold a damp red litmus paper over the substance, if ammonia is present, the litmus paper will turn blue

Question 13

how do you test for halide ions

Answer 13

-add some nitric acid
-then add some silver nitrate
-then a coloured precipitate forms

Question 14

what colour precipitate do chlorides give in the test for halides

Answer 14

white

Question 15

what colour precipitate do bromides give in the test for halides

Answer 15

cream

Question 16

what colour precipitate do iodides give in the test for halides

Answer 16

yellow

Question 17

how to test for carbonates

Answer 17

mix some dilute acid. if carbonate present, mixture will fizz as they will react to produce CO2

Question 18

how do you test for sulfate ions

Answer 18

add dilute hydrochloric acid.
-then add barium chloride solution.
-if sulfate present, a white barium sulfate forms

Question 19

what is flame photometry

Answer 19

it is an instrumental method used to identify ions in a dilute solution. each element produces a unique colour.

Question 20

pros of using flame photometry over flame test

Answer 20

-sensitivity-they can detect small amounts of substances
-accuracy-they give values closer to the true value
-speed

Question 21

what is the general formula for alkanes

Answer 21

CnH2n+2

Question 22

what is the first alkane

Answer 22

methane

Question 23

what is the second alkane

Answer 23

ethane

Question 24

what is the general formula for alkene

Answer 24

CnH2n

Question 25

what is the difference between alkanes and alkenes

Answer 25

alkenes have a C=C double bond

Question 26

can you test alkanes or alkenes with bromine water?

Answer 26

alkenes

Question 27

how do you test alkenes with bromine water

Answer 27

when mixed together, the alkene will decolourise the bromine water from orange to colourless.

Question 28

why does bromine water only react with alkenes

Answer 28

as the alkene double bond breaks to allow the reaction but it cant happen with alkanes as it doesnt have double bonds

Question 29

what is addition polymerisation

Answer 29

this is when alkenes open up their double bonds and join together to form polymer chains

Question 30

what is a polymer

Answer 30

these are substances made by joining lots of small repeating units called monomers.

Question 31

what is condensation polymerisation

Answer 31

this is when two different monomers react together to form bonds between them

Question 32

what are the two reactants when creating polyesters

Answer 32

dicarboxylic acid and diol monomers

Question 33

what is the formula for the ester link when making polyesters

Answer 33

CO2

Question 34

what are some naturally occuring polymers

Answer 34

-DNA which is made from monomers called nucleotides -proteins which is made from monomers called amino acids

Question 35

what are the three different ways to dispose polymers

Answer 35

-Landfill -Incineration -Recycling

Question 36

what are the cons for using landfill for the disposal of polymers

Answer 36

-uses valuable land -polymer waste is nonbiodegradable

Question 37

what are the pros of using incineration for the disposal of polymers

Answer 37

produces useful energy

Question 38

what are the cons of using incineration for the disposal of polymers

Answer 38

may produce harmful or toxic gases

Question 39

what are some pros of using recycling for the disposal of polymers

Answer 39

-reduces amount of crude oil being used -makes more polymers -reduces emissions of greenhouse gases

Question 40

what are some cons of using recycling for the disposal of polymers

Answer 40

-the quality of the new polymer is reduced -over time, the strength of the polymer is reduced

Question 41

what is the general formula for alcohols

Answer 41

CnH2n+1OH

Question 42

what is a dehydration reaction

Answer 42

this is when a mixture of an alcohol and an acid catalyst are heated to then form an alkene and water

Question 43

how are carboxylic acids formed

Answer 43

when alcohols are oxidised which will then form carboxylic acids

Question 44

what is the general formula for carboxylic acids

Answer 44

CnH2n+1COOH

Question 45

are carboxylic acids weak or strong

Answer 45

weak

Question 46

what do you call the ions formed when ethanoic acid is ionised

Answer 46

ethanoate

Question 47

what do you call the salt formed when ethanoic acid is reacted potassium carbonate

Answer 47

potassium ethanoate

Question 48

what process is used to make ethanol

Answer 48

fermentation

Question 49

how do you make a solution of ethanol using fermentation

Answer 49

-mix yeast and glucose in a container -leave this in a warm place with no oxygen. if there is a presence of oxygen, ethanoic acid is formed -when the reaction is finished, you can collect the ethanol

Question 50

why does nanoparticles having a high surface area to volume ration good?

Answer 50

as more of their atoms are in contact with the substances. this can make them good catalysts

Question 51

why are fullerenes important in nanomedicine

Answer 51

they can deliver drugs right ito the cells where thery are needed

Question 52

what are some cons of nanomedicine

Answer 52

the way nanoparticles affect the body isnt fully understood

Question 53

what is the word equation for ethanol

Answer 53

glucose= ethanol+carbon dioxide

Question 54

how is fractional distillation used to concentrate ethanol

Answer 54

place it in fractional column ethanol has a lower boiling point so it will be seperated from the water