Organic chemistry (paper2) Flashcards
(140 cards)
1
Q
Name 4 products made from crude oil
A
Plastics, petrol , cosmetics and pharmaceuticals
2
Q
Where do we find crude oil?
A
In rocks
3
Q
Is crude oil finite or non-finite
A
Finite
4
Q
How is crude oil formed?
A
Over millions of years from the remains of tiny sea creatures called plankton which were buried in mud
5
Q
What is crude oil
A
A mixture of molecules called hydrocarbons
6
Q
What is methane made up of?
A
One carbon atom covalently bonded to 4 hydrogen atoms
7
Q
What are hydrocarbons?
A
Molecules made up of hydrogens and carbons only
8
Q
Why are alkanes saturated?
A
Carbon atoms are fully bonded to hydrogen atoms(max amount of hydrogens as their can be)
9
Q
Name the first four alkanes in order
A
.methane (one carbon atom)
.Ethane (2)
.Propane(3)
.Butane(4)
10
Q
What is viscosity?
A
Viscosity is the thickness of the fluid (the higher the thicker)
11
Q
What happens to the viscosity of the hydrocarbon molecule as they get bigger
A
.They get more viscous(they flow slowly)
12
Q
What is flammability?
A
How easily a substance combusts
13
Q
What happens to the flammability as the size of the hydrocarbon increases
A
.Flammability decreases
14
Q
What hydrocarbon molecule is used in Bunsen
burners?
A
Methane
15
Q
What is boiling point?
A
The temperature at which a liquid turns into a gas
16
Q
What happens to the boiling points as the hydrocarbons get bigger
A
Boiling point increases
17
Q
Are methane, ethane, propane and butane gases at room temperature? if so why?
A
Yes, because they have a boiling point lower than room temperature
18
Q
Name three items which run on hydrocarbon fuels?
A
Ships cars and planes
19
Q
What do hydrocarbon fuels release when combusted?
A
Energy
20
Q
What happens if the oxygen is unlimited?
A
The reaction produces carbon dioxide and water (this is called complete combustion)
21
Q
What is the equation for alkanes
A
C(N)H(2n+2)
22
Q
Name the general formulae for a complete combustion reaction of a hydrocarbon
A
Hydrocarbon + oxygen gives carbon dioxide + water (+energy)
23
Q
Balance this (C3H8+02 gives CO2 plus H20)
A
C3H8+502 gives 3CO2 + 4H20
24
Q
What do we need to do to the hydrocarbons in crude oil in order for them to be useful?
A
Separate them via a technique called fractional distillation
25
Where does fractional distillation usually take place?
In huge fractionating columns which we usually find in oil refineries
26
Explain all the steps of the fractional distillation of crude oil
.First we heat the crude oil to a very high temperature causing it to boil,
All the hydrocarbons evaporate and turn into a gas
.Crude oil vapour is now fed to the fractional distillation column, column is hotter at the bottom and cooler at the top
.The hydrocarbon vapours rise up the column and condense once they reach their boiling point
.The liquid fractions are then removed
.The remaining hydrocarbons then move up the column and condense once they reach their boiling point
. Very long chain hydrocarbons are removed at the bottom of the fractionating column
. Very short chain hydrocarbons do not condense (they have very low boiling points)
27
Where are very long chain hydrocarbons with very high boiling points removed?
At the bottom
28
Where are short chain hydrocarbons with very low boiling points removed?
They do not condense, they leave the column as gases they don't condense rise straight away, (have very low boiling points)
29
What do the fractions contain
Hydrocarbons with a similar number of carbon atoms
30
Give some examples of some fuels that some fractions are used as
Petrol and diesel (for cars)
.kerosene(used as jet fuel for planes)
. Heavy fuel oil is used to power ships
.Liquified petroleum gas (is used in camping stoves)
31
explain another thing that fractions can be used as?
Feedstock for the petrochemical industry
32
Explain what is meant by feedstock?
A chemical that is used to make other chemicals
33
. Give items which feedstock fractions are used to make?
.solvents
.lubricants
.Detergents
.Polymers
34
Why may we use cracking?
To break up long chain hydrocarbons since they are not flammable and cannot make good fuels
35
What happens in cracking
A long chain hydrocarbon is broken down to produce a smaller and more useful hydrocarbon and an alkene
36
What else is produced when cracking?
An alkene
37
What do we use in catalytic cracking
High temperature and a catalyst
38
What is the job of the catalyst?
To speed up the reaction
39
What do we use in steam cracking?
High temperature and steam
40
What do alkenes have?
A double covalent bond between two carbon atoms
41
Why are alkenes useful?
They can be used to make chemicals like polymers and are used as a starting material for other useful chemicals too.
42
Are alkenes more or less reactive than alkanes?
They are more reactive due to double bound
43
Explain the experiment in which we can test for alkenes?
By shaking the substance with bromine water which is orange.
| If an alkene is present the bromine water turns colourless.
44
What is the general formulae for alkenes
C(N)H(2N)
45
Where is the covalent bond?
between the carbon atoms
46
Name the molecular formulae of propene
C3H6
47
Why are alkenes unsaturated molecules?
Because they have two fewer hydrogen atoms than the alkane with the same number of carbon atoms
48
Which part of the alkene is the alkene functional group and why is it that?
The double bond is the alkene because that determines how it reacts .
49
What is meant by a functional group?
The part of a molecule that determines how it reacts
50
Describe what is meant by a homologous series?
Where all the members of the series have the same functional group e.g.(for alkenes its the double covalent bond)
51
What does each member in the homologous series have?
An extra carbon atom and two extra hydrogen atoms than previous alkene
52
What happens when we combust alkenes?
They produce carbon dioxide and water and also produces unburnt carbon particles meaning that alkenes burn in air with a smoky flame
53
Why are unburnt carbon particles produced?
Due to incomplete combustion
54
What name is used to describe the reaction when an alkene reacts with hydrogen?
A hydrogenation reaction
55
What is required for this hydrogenation reaction?
A nickel catalyst and 150 degrees celcius
56
What happens in this reaction?
The two hydrogen atoms add across the double bond and the carbon to carbon double bond is converted to a carbon to carbon single bond converting ethene to ethane.
57
Give the general formulae for the hydrogenation of an alkene
Alkene + hydrogen produces Alkane
58
Are alkenes a homologous series?
Yes
59
Why do all alkenes react in the same way?
They all have a double covalent bond (same functional group)
60
What happens when we add water too ethene in a hydration reaction
.We produce ethanol (an alcohol)
61
Name the conditions for the hydration of ethene
The water has to be in the form of steam, the temperature must be at around 300 degrees Celsius and the pressure around 70 atmospheres
62
What catalyst do we use?
Phosphoric acid
63
Is the reaction reversible (hydration of ethene)
Yes
64
What can we do with unreacted ethene and steam if the reaction is reversible?
We can pass them back through the catalyst to increase the yield of ethanol
65
look at the freesciencelessons picture of the hydration of ethene just in case
nothing to say
66
What happens when we react ethene with chlorine(halogen)
The two chlorine atoms in the chlorine molecule have been added across the double bond and the carbon to carbon double bond is now a carbon to carbon single bond and dichloroethane is formed
67
What is formed when ethene reacts with bromine
dibromoethane
68
What is formed when iodine reacts with ethene
diiodoeethane
69
Name three uses of alcohols?
In fuels, solvents and in alcoholic drinks
70
Are the alcohols a homologous series?
Yes
71
What does this mean?
Means they all have the same functional group? e.g.(OH)
72
Give the structural formulae for methanol
CH3OH
73
Give the structural formulae for propanol
CH3CH2CH20H
74
give one advantage of producing ethanol via the hydration of ethene
produces a high yield of ethanol
75
Give two disadvantages of producing ethanol via hydration of ethene
Requires a high temperature so lots of energy and uses ethene from crude oil which is a non-renewable source
76
Name another way we can produce ethanol?
Via fermentation
77
Describe the process of fermentation
In fermentation we start with a sugar solution such as glucose and mix this with yeast, the yeast converts the sugar solution to a solution of ethanol, Carbon dioxide gas is also produced.
78
Name two conditions for fermentation
Temperature of around 30 degrees Celsius, reaction must take place in anaerobic conditions (without oxygen)
79
Give two advantages of producing ethanol via fermentation
. Low temperature (does not require lots of energy)
| . The sugar from this reaction comes from plants and therefore is renewable
80
Give a disadvantage of producing ethanol via fermentation
A aqueous solution of ethanol is produced *ethanol dissolved in water* so we have to distillate the solution to purify the ethanol and that requires energy
81
Are alcohols soluble in water? what do they from when reacted with water
They from neutral solutions and yes they are soluble in water
82
What decreases as the number of carbon atoms increases
solubility
83
What do we see when ethanol is reacted with sodium?
We see bubbles of hydrogen gas being produced
84
What product is made when ethanol and sodium react?
Sodium ethoxide plus hydrogen
85
What does propane and sodium give when reacted together?
Sodium propoxide plus hydrogen
86
What does sodium and butane produce?
Sodium butoxide plus hydrogen
87
Give a good example of an oxidising agent?
Acidified potassium dichromate
88
What do alcohols produce when reacted with an oxidising agent?
They produce a carboxylic acid plus water
89
What does methanol give when reacted with an oxidising agent?
Methanoic acid plus water
90
What does propanol and butanol give when reacted with an oxidising agent?
butanoic acid plus water
| . Propanoic acid plus water
91
What is produced when combusting a alcohol
Carbon dioxide plus water, energy is also released
92
LOOk at diagrams freescincenlessons for carboxylic acids and more before
nothing to say
93
Are the carboxylic acids a homolgous series
Yes they all have the same functional group(COOH)
94
Give the structural formulae for Methanoic acid and and propanoic acid.
HCOOH
| CH3CH2COOH
95
What are carboxylic acids in water?
They are weak acids
96
What happens when when ethanoic acid is in solution
| What type of reaction?
It ionises to form ethanoate ion and hydrogen plus ions in a reversible reaction
97
Why are carboxylic acids weak acids?
They only partially ionise in aqueous solution
98
So they have a higher PH than strong acids e.g. hydrochloric acid
cba read the question its an info grab
99
What is the general formulae when a carboxylic acid reacts with a carbonate
we get a salt a carbon dioxide gas and water
100
What do we get when propanoic acid reacts with potassium carbonate
We get potassium propanoate plus carbon dioxide plus water
101
Is potassium propanoate a salt?
Yes
102
What do we produce when we react a carboxylic acid with an alcohol
we make an ester plus water
103
Where are esters used
In foods as they have a pleasant smell
104
What is the genera formulae for an alcohol and a carboxylic acid reacting together
they form ester plus water
105
what does ethanoic acid plus ethanol give
Ethyl ethanoate plus water
106
What is required for this reaction?
Sulfuric acid as a catalyst, this is a reversible reaction
107
Name three uses of polymers?
Plastic cups, plastic bottles and also shavers
108
How are polymers made?
By joining together thousands of small identical molecules, known as monomers
109
What are the monomers in addition polymers?
They are alkenes
110
Give a difference between the monomer and the addition polymer?
There is no double covalent bond between the two carbon atoms in the polymer however there is in the monomer
111
If the monomer is ethene what do we make?
Poly(ethene)
112
What does the word poly mean?
Many
113
How do we work out the repeating unit?
By getting two carbon atoms next to each other and drawing these out and the hydrogen atoms attached we then put brackets around going through the bond them and put an n in the bottom right corner
114
What does the n after the brackets tell us?
That the polymer consists of a large number of repeating units
115
Why does the repeating unit have the same number of atoms as the monomer?
Because there is nothing else formed in the reaction and everything in the monomer ends up in the polymer
116
Does the repeating unit have a double bond?
No
117
What are condensation polymers made up of?
Monomers too
118
Are the monomers in condensation polymers alkenes
No
119
What happens when these monomers react(condensation polymers)
Small molecules such as water are lost
120
Are all the monomers the same in condensation polymers?
No, we start with two different monomers. Each monomer has two of the same functional group
121
What can we do instead of draw the full structure of them monomers?
Put a box in the middle representing carbon chains and only show the functional groups
122
What condition do we need for to make water?
An OH and a H
123
What is the structure of glycine
H2NCH2COOH
124
How many functional groups are there in glycine and name them
2,Amine group and carboxylic acid group
125
Describe the amino functional group
A nitrogen atom covalently bonded with two hydrogen atoms
126
Give an example of an amino acid
Glycine
127
Why can amino acids react to form a condensation polymer?
They have two functional groups
128
Watch free science lessons on amino acids
dkjb
129
Why do we call the polymer made up of glycine a polypeptide?
It is only made up of one type of amino aicd
130
Do all amino acids have two functional gorups?
Yes
131
What polymer is made up of amino acid monomers?
Protein
132
What are long chain polypeptides known as?
Proteins
133
Name a natural occuring poymer?
Protein
134
Where is DNA found
in almost all living organisms animals plants bacteria fungi including some viruses
135
What do some viruses have instead of DNA
A related molecule
136
What does DNA do?
Decodes the genetic instructions that living organisms need to develop and to function
137
What does DNA contain?
Two polymer chains made from monomers called nucleotides
138
Name the four different types of nucleotide monomers
GATC
139
What do the two polymer chains in DNA do?
wrap around each other to form a double helix
140
What is starch and cellulose polymers of
glucose arranged in a slightly different way
