organic chemistry real Flashcards
(135 cards)
1
Q
what is a hydrocarbon
A
compound formed with only hydrogen and carbon atoms
2
Q
gen formula for alkane
A
Cn H2n
3
Q
2 features of all alkanes
A
saturated compounds-each carbon atom forms 4 single covalent bonds
-a homologous series-organic compounds that react similarly
4
Q
viscosity as hydrocarbon(gloopiness) gets longer
A
increases
5
Q
volatility(how easily turns to gas) as hydrocarbon gets longer
A
decreases
6
Q
flammability as hydrocarbon gets longer
A
decreases
7
Q
bp and mp as hydrocarbon gets longer
A
increases
8
Q
why are hydrocarbons used as fuels
A
it releases lots of energy when completely combusted
8
Q
what are shorter hydrocarbons with lower bp used for eg
A
as bottled gases under pressure as liquids in bottles
9
Q
what is the equation for complete combustion of hydrocarbons
A
hydrocarbon+oxygen—–>co2 +water vapour
10
Q
what is crude oil
A
a fossil fuel formed from remains of plants and animals mainly plankton made of mainly hc(alkanes)
11
Q
how was crude oil formed
A
high temps/pressure on remains that died millions of years ago buried under mud turns them to crude oil
12
Q
how is crude oil extracted
A
drilled up from rocks
13
Q
what are cons of fossil fuels like crude oil
A
take long to make so used faster than made meaning they are finite
14
Q
what is fractional distillation
A
the way compounds in crude oil are seperated
15
Q
1st step of fractional distillation
A
oil heated until most turns to gas and liquid is drained off
16
Q
describe the temp conditions of the fractionating column
A
hot at bottom
cool at top
17
Q
2nd step of fractional distillation
A
gases enter fractionating column
18
Q
what happens to longer hydrocarbons in fractional distillation
A
condense back to liquids and drain out near bottom
19
Q
what happens to shorter hydrocarbons in fractional distillation
A
condense and drain out at top where its cooler
20
Q
what are you left with at the end of fractional distillation
A
crude oil mixture is seperated into diff fractions with mixture of hc with similar bp and no of carbons
21
Q
why do longer hc and shorter condense at different fractions
A
They condense at regions lower than their boiling points
22
Q
what hc condense at the top in fractional distillation
A
lpg
23
Q
what hc condense in the middle in fractional distillation
A
petrol
kerosene
diesel oil
24
what hc condense at the bottom in fractional distillation
heavy fuel oil which can be
heating,fuel or lubricating oil
25
what is a petrochemical
A petrochemical is a substance made from crude oil, via chemical reactions.
26
what is a feedstock
A feedstock is a raw material used to provide reactants for an industrial reaction
27
what does the petrochemical industry use hydrocarbons from crude oil for
feedstock for new compounds like polymers
solvents
lubricants
detergents
28
what are organic compounds
compounds containing carbon
29
why do you have so many products from crude oil
carbon atoms bond to form different groups called homologous series
30
what is cracking
splitting of less useful high supply long chain hc from frac distillation to more useful shorter hc
31
what does cracking produce
alkane +alkene
32
what are uses of alkenes
starting materials for other compounds
polymers
33
what type of reaction is cracking and what are the types
thermal decomposition
-steam and catalytic
34
1st 2 Steps for catalytic cracking
heat long chain hc to gas
pass vapour across hot powdered aluminium oxide catalyst
35
step 3 and 4 of catalytic cracking
long chain molecules split
on surface of catalyst powder as specks
36
Describe process of steam cracking
vapourise hc
mix these with steam
heat to a high temp
37
why are alkenes called unsaturated
they have same no of carbons and 2 fewer hydrogens due to double bond
38
what is the functional group of alkenes
C=C
39
why are alkenes more reactive than alkenes
the double bond can open to be a single bond so carbons can bond to other atoms
40
alkene combustion compared to alkane
is the same
products are water and co2
41
what may cause alkenes to undergo incomplete combustion
burning in air
42
equation for incomplete combustion of alkenes
alkene+oxygen --->carbon +carbon mooxode+carbon dioxide +water
43
what are the results of incomplete combustion of alkenes
-smoky yellow flame
-less energy released than complete
44
what is a functional group
group of atoms in a molecule that determine how it will react
45
how do alkenes mostly react
via addition reactions
where carbon double bond is opened to leave single bond and and new atom added to each carbon
46
what happens when alkenes are hydrogenated
forms saturated alkane in the presence of a catalyst(eg platinum or nickel)
47
what are the alkene addition reactions
hydrogen
halogens-specifically bromine
steam
48
alkene reaction with halogen and eg
c=c bond splits to bond with halogen atom
and produces saturated molecule
eg
ethene +bromine---->dibromoethane
49
bromine water reaction with alkane vs alkene
-stays orange with alkane/saturated compound
-goes colourless when alkene is added
50
alkene reaction with steam
water is added across double bond(which split to be single bonds) and alcohol formed
51
+eg of alkene reaction with steam
ethene+steam
and then passing it over phosphoric acid catalyst+high temps/pressure
-------->ethanol
52
what happens after ethanol is formed in alkene+steam
mixture passed from reactor to condenser where ethanol and water condense(higher bp) leaving unreacted ethene gas
53
what is ethene addition reaction with steam a way of
-a way of industrially making ethanol
54
what happens with unreacted ethene gas in it and the alcohol in ethene+steam
-recycled back into reactor
-purified from mixture by fractional distillation
55
what is polymerisation
monnomers joining together to form long molecules called polymers
- addition often needs high pressure and catalyst
56
eg of a polymer and its monomer
what what it is based from
plastics
monomers are alkenes
usually carbon based
57
what are the monomers that make up addition polymers
unsaturated
58
how do unsaturated monomer molecules perform addition polymerisation
they open up double bonds and join to form polymer chains
59
for addition polymerisation what is the difference in displayed formulas between polymers and monomers
polymers have no double bond
monomers have
60
what is the functional group of carboxylic acids and what do they end with
-COOH
end with anoic acid
61
describe the structure of carboxylic acids func group
c is diagonally double bonded to o at the top
the same c is single bonded to oh at the bottom
it is always furthest right
62
what do carboxylic acids react the same as but what is the difference
acids
-form salts ending in anoate
eg sodium ethanoate
63
what type of acids are carboxylic acids and why
weak
when they dissolve in water they ionise/release h+ ions but incompletely so they are less acidic than strong acids of same con
64
what is the functional group of esters
-coo
65
what make up esters
alcohol and carboxylic acids
66
what catalyst is used in esterification
concentrated sulfuric acid
67
what is the reaction to form esters
alcohol+carboxylic acid----->ester +water
conc sulfuric acid catalyst
68
ethanoic acid +ethanol forms
ethyl ethanoate
69
what would you see when sodium carbonate is added to aq solution of methanoic acid
effervessence as co2 gas is given off
70
what does condensation polymerisation involve
involves monomers with different functional groups joining to form a polymer and small molecule
71
what happens in condensation polymerisation involving small molecules
monomers react and form bonds forming polymer chains
every bond formed releases small molecule
(eg water)
72
what do the simplest types of condensation polymers contain
-2 monomer types with same functional groups
73
what is a diol
a molecule which contains two alcohol functional groups such as ethane diol
74
how is polyester formed by condensation polymerisation
diol+dicarboxylic acid---->condensation polymer +water
75
what is a dicarboxylic acids
a molecule that contains 2 carboxylic functional groups
76
what is an example of a condensation polymer
polyester
77
what is the diff in monomers between addition and condensation polymerisation
addition-only 1 monomer with c=c bond
condensation=2 monomer types with same func groups or 1 with diff
78
what is the diff in products formed between addition and condensation polymerisation
addition-1 formed
condensation-2 formed
79
what is an example of a naturally occuring polymer
-amino acids
polypeptides
DNA molecules
80
how are amino acids formed
using 2 func groups
amino group and acidic carboxyl group
81
what is an amino group and a carboxyl group
NH2
-COOH
82
how are polypeptides formed
amino acids by condensation polymerisation
83
what is the smallest/simplest amino acid
glycine
84
what are examples of proteins in the body
enzymes
haemoglobin
antibodies
85
what is the diff between a polypeptide and protein
polypeptide is a protein monomer
86
what gives proteins diff properties and shapes
order of amino acids
87
what does dna have and do
genetic instructions
allows organism to develop and operate
88
what makes up dna
2 polymer chains of monomers called nucleotides
89
what makes up nucleotides
molecules called bases
a c t and g
phosphate
sugar
90
what gives a polymer its double helix structure
bases on diff polymer chain form cross links holding nucleotide together
91
what do the bases act as
code for the organisms genes
92
what are sugars
small molecules that contain carbon oxygen and hydrogen
93
what is the term for the simplest unit of sugar
monosacharide
94
how are starch and cellulose made by smaller sugars
by condensation polymerisation to form polysacharides
95
properties of polyethene/thene
strong and easy to shape
useful as a plastic
96
uses of polythene
carrier bags
drink bottles
dustbins
cling film
washing up bowls
97
property of polypropene
strong and tough as a plastic
98
uses of polypropene
carpets
milk crates
ropes`
99
uses of the first 4 alcohols
as fuels
100
● uses of methanol:
: chemical feedstock, in anti-freeze, to make biodiesel
101
● uses of ethanol:
● Ethanol: the main alcohol in alcoholic drinks, used as a solvent and fuel
102
structure of low density polythene
branched polymer chains
randomly arranged molecules
103
structure of high density polythene
less branching of polymer chains
closely lined molecules
104
uses of low density polythene
and properties
-Most carrier bags, bubble wrap
-Flexible, unreactive, can be made into films
105
properties of high density polythene
and uses
Strong, flexible, resists shattering, resists chemical attack
Plastic bottles, pipes, buckets
106
properties of thermosoftening polymers
melt when heated
recyclable
107
why do thermosoftening polymers melt when heated
no covalent bonds betw neighbouring polymer molecules so can move over each other when heated and the plastic melts.
108
properties of thermosetting polymers
char and burn but dont melt when heated
strong covalent bonds
109
uses of thermosetting polymers
electrical plugs
110
properties of carboxylic acids
unpleasant smells and tastes
higher bp than water
not flammable
111
how is ethanol from alcoholic drinks made
fermentation in presence of yeast
forms ethanol +co2
112
equation for fermentation
glucose----->ethanol+carbon dioxide
yeast catalyst
113
why must fermentation be warm
as yeast is a living microorganism and so its enzymes dont denature
114
pros and cons of fermentation
cons
-slow/emits co2 as waste
pros
renewable source of energy
only needs heating to 37 degrees
115
pros and cons of ethene+water
cons-
non renewable/needs lots of energy
pros-
faster than fermentation
100% atom economy
116
alcohols react with pottasium dichromate(oxidising agent)to produce
a carboxylic acid
117
alcohols react with air(combustion/complete/incomplete) to produce
co2 +water
combustion
incomplete=soot/carbon monoxide
118
ethanol +sodium
colourless sodium ethoxide solution+h2 gas(fizzes)
119
alcohol+water
ph7
neutral solution
120
colour change in alcohol oxidation
can happen in air so none
-oxidising agent acidified pottasium dichromate
orange to green
121
alcohol formula
cNh2N+1OH
122
carboxylic acid formula
cNh2N+1COOH
n=carbon atoms -1
123
ph strength order
ethanol
nitric
hcl
sulfuric
methanoic
hcl
sulfuric
nitric
methanoic
ethanol
124
use of ethanoic acid
making vinegar
making esters
125
test for carboxylic acid
react with sodium bicarbonate-see brisk effervescence
react with sodium carbonate to produce co2
126
eg of naturally occuring polymers
proteins
carbs
dna
127
eg of polypeptide
protein
128
peptide bond
ocnh
129
how many nucleotides are present in Dna
4
130
how do nucleotides form polymers and what do we call the polymer
lots of monomers join to form polynucleotide by condensation polymerisation
131
how many bases code for amino acid
3
132
what makes the backbone of a polynucleotide
sugar and phosphate
133
why do a and t attract
and c and g
2 attractions between a-t
3 between c-g
these are imf(h-h bonds)
135
