feb mocks Flashcards
1
Q
what is a hydrocarbon?
A
a compound of hydrogen and carbon only
2
Q
what is the functional group of an alcohol?
A
-OH
3
Q
how can ethanol be oxidised?
A
- combustion
- microbial oxidisation
- chemical oxidisation
4
Q
what are the two methods of manufacturing ethene?
A
- hydration of ethene
- fermentation of glucose
5
Q
what are the conditions needed for the hydration of ethene
A
- 300 degrees
- 65 atm pressure
- phosphoric acid catalyst
6
Q
what are the advantages of the hydration of ethene?
A
- one product (pure)
- continuous process
7
Q
what are the disadvantages of the hydration of ethene?
A
- requires a lot of energy
- non-renewable raw material
8
Q
what is the equation for the hydration of ethene?
A
C2H4 + H2O –> CH3CH2OH
9
Q
what are the conditions for the fermentation of glucose?
A
- yeast
- 30 degrees
- anaerobic
10
Q
what are the advantages of the fermentation of glucose?
A
- renewable raw material
- less energy required
11
Q
what are the disadvantages of the fermentation of gluose?
A
- impure ethanol
- batch process
12
Q
what is the equation for the fermentation of glucose?
A
C6H12O6 —yeast—> 2C2H5OH + 2CO2
13
Q
what catalyst is required for the hydration of ethene?
A
phosphoric acid
14
Q
what flame colour is the combustion of ethene?
A
blue
15
Q
what is the equation for the complete combustion of ethanol?
A
ethanol + 3oxygen –> 2carbon dioxide +3water
16
Q
what is the equation for microbial oxidation of ethanol?
A
ethanol + 2[O] –> ethanoic acid + water
17
Q
what is the equation for chemical oxidation of ethanol?
A
ethanol + 2[O] –> ethanoic acid + water
18
Q
what is the oxidising agent in the chemical oxidisation of ethanol?
A
potassium dichromate (VI)
19
Q
what does the chemical oxidisation of ethanol require (other than the oxidising agent)?
A
- dilute sulphuric acid
- water bath
20
Q
what is the colour change of chemical oxidisation of ethanol?
A
orange -> green
21
Q
what is the functional group of carboxylic acids?
A
COOH
22
Q
what happens when a carboxylic acid reacts with a metal?
A
same as normal acid; forms a metal __oate + hydrogen
23
Q
what happens when carboxylic acid reacts with a metal carbonate?
A
same as a normal acid; forms a metal __oate + carbon dioxide + water
24
Q
what is the functional group of an ester?
A
COO
25
how fast do carboxylic acids react and why?
slower/less violently than other acids bc they're weak acids
26
how are esters produced?
alcohol + carboxylic acid (+ acid catalyst - eg sulphuric acid)
27
what is a diol?
has OH at both ends
28
what is a dicarboxylic acid?
has -COOH at both ends
29
what do you need to make a polyester?
a dicarboxylic acid and a diol
30
what is the type of polymerisation used to form polyesters?
condensation polymerisation
31
what are the products of condensation polymerisation?
a polyester and water
32
what kinds of polyesters are biodegradable?
biopolyesters
33
are all polyesters biodegradable?
no
34
how is an addition polymer formed?
by joining p many small molecules called monomers
35
how reactive are polymers?
they are inert (unreactive) because of their C-C bonds
36
what is an exothermic reaction?
one that releases heat/heat is given out ; more energy is released forming new bonds than is taken in breaking bonds
37
what are endothermic reactions?
reactions than take in heat energy; more energy is taken in breaking bonds than is released making them
38
do exothermic reactions have a positive or negative energy change in kJ/mol?
negative
39
what is the equation for heat energy change?
Q=mcΔt
40
what is meant by the term homologous series?
- same general formula
- similar chemical reactivity
- same trend in physical properties
- same functional group
41
what is an isomer?
a substance with the same molecular formula but a different displayed formula
42
what is crude oil a mixture of?
hydrocarbons
43
what are the names of the fractions of crude oil in order of increasing RFM?
- refinery gases
- gasoline
- kerosene
- diesel
- fuel oil
- bitumen
44
what is the use of refinery gases?
fuel for heating/cooking
45
what is the use of gasoline?
fuel for cars
46
what is the use of kerosene?
fuel for planes
47
what is the use for diesel?
fuel for lorries/trains
48
what is the use for fuel oil?
fuel for ships
49
what is the use of bitumen?
making roads
50
what is the trend in colour of crude oil with increasing RFM?
gets darker
51
what is the trend in BP in crude oil with increasing RFM?
increases
52
what is the trend in viscosity of crude oil with increasing RFM?
increases
53
what is a fuel?
a substance that releases heat energy when burned
54
what are the possible products of complete combustion of hydrocarbons?
- carbon dioxide
- water
55
what are the possible products of incomplete combustion of hydrocarbons?
carbon monoxide and water
56
why do car engines allow nitrogen and oxygen to react?
the temperature reached is high enough to form oxides of nitrogen
57
why can sulphur dioxide form from the combustion of hydrocarbons?
impurities in the hydrocarbon
58
what are the conditions needed for cracking?
- 650 degrees
- aluminium oxide catalyst
59
what is the general formula for alkanes?
CnH2n+2
60
how do you make alkanes react with halogens?
UV light
61
what kind of reaction is the reaction between alkanes and halogens?
substitution
62
what is the general formula for alkenes?
CnH2n
63
what kind of reaction is the reaction between bromine and alkenes?
addition
64
how can bromine water be used to distinguish alkenes from alkanes?
alkanes can't react with bromine without UV light so no colour change, alkenes make the solution go orange -> colourless
65
what is the effect of changing temperature on the rate of reaction?
higher temperature means a higher rate of reaction because the particles have more kinetic energy so they collide at the activation energy more frequently, so there are more successful collisions per unit time
66
what is the effect of changing the surface area on the rate of reaction?
greater surface area means a higher rate of reaction because more of the reactants are exposed so there are more frequent collisions so there are more successful collisions per unit time
67
what is the effect of concentration on rate of reaction?
higher concentration = higher rate of reaction because there are more particles in the same volume so there are more frequent collisions so there are more successful collisions per unit time
68
what is the effect of pressure on the rate of reaction?
higher pressure= higher rate of reaction because there are the same number of particles in a smaller volume so there are more frequent collisions so there are more successful collisions per unit time
69
what is a catalyst?
a substance that increases the rate of reaction but remains chemically unchanged
70
how does a catalyst work?
it provides an alternative pathway with a lower activation energy
71
what is a covalent bond?
the strong electrostatic attraction between positive nuclei and shared pairs of electrons
72
can covalent compounds conduct electricity (normally)?
no
73
what is the test for ammonia?
place damp red litmus paper in the sample of the gas, it turns blue
74
what is the test for chlorine?
place damp blue litmus paper in a sample of the gas, it turns white
75
what is the flame colour of lithium ion?
red
76
what is the flame colour of sodium ions?
yellow
77
what is the flame colour of potassium ions?
lilac
78
what is the flame colour for calcium ions?
orange-red
79
what is the flame colour for copper?
blue-green
80
what is the test for ammonium?
- dissolve sample in water
- add some sodium hydroxide and warm it
- test gas evolved with damp red litmus paper (test it for ammonia)
- litmus paper will turn blue
81
how do you test for chlorine?
- dissolve the sample in water
- add nitric acid
- add silver nitrate solution
- a white precipitate will form
82
how do you test for bromine ions?
- dissolve sample in water
- add nitric acid
- add silver nitrate
- cream precipitate formed
83
how do you test for iodine ions?
- dissolve sample in water
- and nitric acid
- add silver nitrate solution
84
how do you test for copper ions (not flame test)?
- dissolve sample in water
- add a few drops of sodium hydroxide solution
- forms blue precipitate
85
how do you test for iron (II) ions?
- dissolve sample in water
- add a few drops of sodium hydroxide
- forms green precipitate
86
how do you test for iron (III) ions?
- dissolve sample in water
- add a few drops of sodium hydroxide
- brown precipitate formed
87
how do you test for water?
add anhydrous copper sulphate, goes from white to blue
88
how do you test for carbonates?
- add hydrochloric acid and look for fizzing
- if fizzing, bubble gas through limewater (turns cloudy)
89
how do you test for sulphates?
- add hydrochloric acid and look for fizzing
- if no fizzing, add barium chloride solution, white precipitate formed
