Organic Chemistry Flashcards
(145 cards)
1
Q
Define organic (old and new definitions)
A
old - chemicals that come from living organisms
new - compounds based on carbon, with other elements such as H, O, N
2
Q
Define homologous series
A
a group of chemicals with the same general formula, a pattern of physical properties and similar chemical properties
3
Q
Define hydrocarbons
A
compounds consisting of only C + H atoms
4
Q
Define alkanes
A
hydrocarbons with only single bonds
5
Q
How do you name organic substances?
A
prefix (additional atoms)
root of word (noº of C atoms)
suffix (homologous series)
6
Q
What do you call an alkane with 2 C atoms?
A
ethane
7
Q
What is the general formula for alkanes?
A
CₙH₂ₙ ₊ ₂
8
Q
Fill in the root of the word for each of the number of C atoms:
noº of C atoms
1 -
2-
3 -
4 -
5 -
6 -
7 -
8 -
9 -
10 -
A
1 - meth
2- eth
3 - prop
4 - but
5 - pent
6 - hex
7 - hept
8 - oct
9 - non
10 - dec
9
Q
Write the structural formula for butane
A
CH₃CH₂CH₂CH₃ or CH₃(CH₂)₂CH₃
10
Q
What are the physical properties of alkanes?
What are the mpt, viscosity, volatility, and color like?
A
- covalent discrete
mpt
- increases due to more IMFs
viscosity
- increrases due to more IMFs and larger molecules inter-twine
volatility
- decreases due to increasing bpt
color
- colorless → yellow → black
11
Q
Define viscosity
A
resistance to liquid flow
12
Q
Define volatility
A
ease of turning into a gas
13
Q
To recap: What are the properties of covalent discretes?
A
- low mpt
- insulator
- soluble in oils
14
Q
★ New topic: Isomers ★
A
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15
Q
Define isomers
A
compounds with the same molecular formula but different arrangement of atoms (dif. structural formula)
16
Q
Define prefix in the context of naming chemicals
A
any additional atoms not yet included
17
Q
Trick to remember isomers:
A
cannot go through carbons in a line without lifting the pen
18
Q
What are the rules to name isomers?
A
number where ‘extra’ atoms are - (number of extra Cs)(number of extra Cs in a row)(yl)(number of Cs in a row)(homolugous series)
19
Q
What is the method for measuring the enthalpy change for metal + acid?
A
1) measure 10 cm³ of acid into caliometer
2) measure approximately x g (0.50 g) of metal
3) measure the initial temperature of the acid
4) add metal to acid, start timing
5) record temperature every 15 seconds until temp. starts to decrease (3 readings after it starts decreasing)
20
Q
★ New topic: Reactions of Alkanes ★
A
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21
Q
Are alkanes usually reactive or unreactive?
A
unreactive
22
Q
Why are alkanes generally unreactive?
A
because they only contain strong single covalent bonds (saturated)
23
Q
In what forms can energy be provided to make alkanes react (Ea)?
A
1) heat
2) electricity
3) light
24
Q
What are the 3 types of reaction that alkanes undergo?
A
1) substitution
2) combustion
3) decomposition
25
Give an example of substitution with ethane and chlorine
ethane + chlorine −U.V. light→ chloroethane + hydrogen-chloride
26
Alkane + halogen →
haloalkane + hydrogen halide
27
Methane + bromine →
bromomethane + hydrogenbromide
28
Multiple prefixes →
arrange alphabetically (ignoring di, tri, tetra, etc.)
29
Propane + fluorine
either 1- fluoropropane
or 2- fluoropropane
30
★ **New topic: Combustion** ★
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31
What is the equation for complete combustion?
alkane + oxygen → carbon dioxide + water
32
Pick the correct answer:
butane + oxygen → cardon dioxide + water
or
butane + oxygen → butoxide
butane + oxygen → cardon dioxide + water
OBVI
33
What are the 2 equations for incomplete combustion?
alkane + oxygen → carbon monoxide + water
alkane + oxygen → carbon (soot) + water
34
How could you avoid incomplete combustion with carbon monoxide?
ventillation
35
Why is carbon monoxide toxic?
it replaces oxygen in haemoglobin
36
Why are the downsides to soot when doing incomplete combustion?
damages lungs and damages machinery
37
What does carbon look like?
black solid
38
★ **New topic: Decomposition** ★
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39
What are the conditions needed for decomposition of alkanes?
- heat to 300 ºC
- catalyst of Al₂O₃ / SiO₂
40
What is the equation for decomposition in alkanes?
large alkane → smaller alkane + alkene
41
Complete the equation:
C₁₆H₃₄ −xxxxxx→
C₁₆H₃₄−heat + Al₂O₃ → C₉H₂₀ + C₇H₁₄
42
What is heptene used for? Why is it less useful?
- to make plastic
- less useful because it has low flamibility
43
★ **New topic: Alkenes** ★
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44
Define alkene
hydrocarbons with at least one C ＝C double bond
45
Which alkene does not exist?
methene
46
What is the general formula for alkenes?
CₙH₂ₙ
47
Name the alkene:
C ＝ C − C
|
C
methylprop-1-ene
48
What are the properties of alkenes? (physical and chemical)
physical → same as alkanes (covalent bonds do not affect mpt - for discrete covalent. alkenes have slightly lower bpt due to smaller molecules)
chemical → alkenes contain a double bond
49
What is a double bond from an alkene like?
a single bond which is strong and unreactive and another weaker bond which breaks easily
50
Could one of the bonds in a double bond in alkenes break and leave the other?
yes
51
★ **New topic: Reactions of alkenes** ★
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52
Define saturated
only has single bonds
53
Are alkenes saturated or unsaturated?
unsaturated
54
What causes alkenes to be more reactive than alkanes?
alkenes have a double bond
55
What happens during an addition reaction with halogens in alkenes in terms of bonds?
double bond breaks, one halogen atom joins on either side of where the double bond was
56
Which reaction do alkenes undergo?
addition
57
What is the general formula for an addition reaction with halogens in alkenes? (use ethene)
C₂H₄ + X₂ → C₂H₄X₂
58
Name the chemical:
prop-1-ene + chlorine →
1,2 - dichloropropane
59
What are the differences between addition and substitution reactions? place stars next to the ones which use halogens
1)★ only one product with addition of halogens
2) no additional energy required for addition
3) ★addition forms a dihalo product, substitution forms monohalo product
60
What chemicals can addition occur with?
1) hydrogen halides
2) water
61
What is the suffix for alcohols?
ol
62
What is the test for alkenes?
react substance with Br₂ (aq) (bromine solution / bromine water)
63
Alkene + water →
alcohol
64
What type of light should you **not** use when testing for alkenes?
U. V. light
65
Alkane + Br₂ →
(no U.V. light)
no reaction
66
Alkene + Br₂ →
(no U.V. light)
colorless dihaloalkane
67
Do alkanes affect the color of bromine?
no
68
What do alkenes do to bromine?
alkenes decolorise bromine
69
★ **New topic: Polymerisation** ★
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70
What is another word for plastic?
polymers
71
How does polymerisation occur?
through addition
72
Through polymerisation:
ethene →
polyethene
**important:** it ends in ene but there are no double bonds
73
What does a polymer look like when drawn?
74
monomer →
propene →
polymer
polypropene
75
What letter should a polymer look like when drawn?
H
76
What are the physical properties of polymers?
1) low mpt (covalent discrete), weak IMFs but higher monomers due to large molecules
2) insulator, no charged ions
3) insoluble in water, soluble in oils
77
What are the chemical properties of polymers?
1) unreactive (saturated)
2) combustion → releases CO₂ , releases non-metal oxides (acids)
3) substitution
4) disposed of in land-fill (because it's unreactive). plastic escapes into lakes / rivers
78
★ **New topic: Manufacture of ethanol** ★
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79
What's the first method for the manufacture of ethanol?
direct hydration of ethene
80
What are the conditions needed for ethene to react with water?
1) temperature at 600 ºC
2) concentrated catalyst
3) catalysts of: H₂SO₄ or H₃PO₄
81
What is the name of the reaction for direct hydration of ethene?
addition or hydration
82
What is 100% ethanol used for?
disinfectant / solvent
83
What are the advantages for direct hydration of ethene?
1) continuous process
2) product is pure (no separation needed)
84
What are the disadvantages for direct hydration of ethene?
1) high energy demand
2) ethene comes from cracking
3) alkanes are non-renewable
85
What's the second method for the manufacture of ethanol?
fermentation of sugars
86
What is the catalyst for fermentation of sugars?
yeast
87
ethene + water →
ethanol
88
What is the equation for fermentation of sugars?
sugar −yeast→ ethanol + carbon dioxide
89
Where do you get the sugar for fermentation of sugars?
fruits
90
When doing fermentation of sugars, the ethanol is only 15% pure. Why?
1) fruit isn't 100% sugar
2) ethanol will kill yeast, stopping the process
3) distillation can produce more concentrated ethanol
91
What are the advantages for fermentation of sugars?
1) sugars & fruits provide flavour
2) renewable resources
3) low energy demand
92
The ethanol produced during fermentation of sugars is usually used for...
drinking alcohols
93
What are the disadvantages for fermentation of sugars?
1) batch process (slow)
2) product is a mixture, this mean the ethanol has to be separated
94
★ **New topic: Oxidation of Alcohols** ★
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95
How is oxygen added to a reaction when doing oxidation of alcohols?
by using an oxydizing agent
96
What are the 2 oxidizing agents that could be used during oxidation of alcohols?
K₂Cr₂O₇ or KMnO₄
97
During a non-destructive oxidation of alcohols, an alcohol reacts to create...?
an aldehyde and carboxilic acid
98
During a destructive oxidation of alcohols, an alcohol reacts to create...?
carbon dioxide + water
99
What are the colors of K₂Cr₂O₇ or KMnO₄?
K₂Cr₂O₇ - orange
KMnO₄ - purple
100
What is the suffix for carboxylic acid?
-oic acid
101
What is the suffix for aldehydes?
-al
102
Define reflux (apparatus)
used to heat chemicals and prevent anything from escaping it. round - bottom flask with condenser
103
What colors and charges do K₂Cr₂O₇ or KMnO₄ turn?
K₂Cr₂O₇ - orange Cr⁶⁺→ green Cr³⁺
KMnO₄ - purple Mn⁷⁺→ pink Mn⁶⁺
104
Complete the equation for oxidation of alcohols:
alcohol→
alcohol → apples → vinegar
105
Complete the equations:
acid + metal →
acid + base →
acid + metal carbonate →
acid + metal → salt + hydrogen
acid + base → salt + water
acid + metal carbonate → salt + water + carbon dioxide
106
Methanoic acid + sodium →
sodiummethanoate + hydrogen
107
Methanoic acid + sodium → sodiummethanoate + hydrogen
Write a symbol equation for this reaction
2HCOOH + 2Na → 2HCOONa + H₂
108
★ **New topic: Esterification** ★
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109
What is the general displayed formula of an ester?
O
||
R − C − O − R
first R - any group
second R - any group except H
.
110
What is the equation for esterification?
alcohol + carboxylic acid → ester + water
111
Complete the sentence:
Esterification is an example of a _______________ reaction.
condensation
112
Complete the equation:
methanol + ethanoic acid →
methylethanoate
113
Complete the equation:
ethanol + butanoic acid →
ethylbutanoate
114
What are esters used for?
food flavourings
115
The rate of reaction for esterification is slow, what can be done to increase the rate of reaction?
1) add a catalyst (conc. H₂SO₄)
2) increase temp. (~70 ºC)
3) constant stirring (reactants are immiscible)
116
Condensation polymerisation →
polyester
117
What is the general formula for a polyester
118
★ **New topic: Reaction Rates (kinetics)** ★
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119
A + B →
C + D
120
Define reaction rate
number of moles of product formed per second
or
number of moles of reactant used per second
121
What are the 4 methods for measuring the rate of a reaction?
1) mass change
2) volume of gas
3) solid disappearing
4) color change
122
Give an example of a mass change experiment to measure a rate of a reaction
metal carbonate + acid → salt + water + carbon dioxide
123
Where does the gas go in a mass change experiment to measure a rate of a reaction?
the gas is used up / made
124
In a mass change experiment to measure a rate of a reaction, why is cotton wool placed at the top of the conical flask?
to prevent liquid from leaving
125
What is the rate of a reaction represented by on a graph?
the gradient
126
Define tangent
straight line that has the same gradient as one point on a curve
127
What is the x and y axis of a graph for a mass change experiment to measure a rate of a reaction?
x-axis = time (s)
y-axis = mass (g)
128
Give an example for an experiment of volume of gas to measure the rate of a reaction
metal + acid → salt + hydrogen
129
When measuring the volume of gas of hydrogen, does gas get produced initially?
no
130
What is the apparatus used for measuring the volume of hydrogen produced from metal + acid?
trough
delivery tube
gas jar
conical flask
or
conical flask
delivery tube
gas syringe
131
Give an example for an experiment to measure the rate of a reaction using solid disappearing
metal + water → metal hydroxide + hydrogen
132
What should you measure for an experiment to measure the rate of a reaction using solid disappearing?
time until solid disappears
133
Why is there not a graph for a solid disappearing reaction? Name a down side of this
because there would only be one point, therefore, we can only calculate the average rate
134
What should you measure for an experiment to measure the rate of a reaction using color change?
time until color changes
135
Give an example of a color change experiment to measure rate of reaction
iron (gray) + coppersulfate (blue) → iron(II)sulfate (green) + copper (orange)
135
What is the biggest disadvantage for measuring rate of reaction using color change?
when the color changes, it's subjective
136
★ **New topic: Crude Oil** ★
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137
Define crude oil
a mixture of thousands of hydrocarbons (miscible, alkenes) that comes from the remains of sea-creatures which have reacted to form organic compounds.
138
How do you separate crude oil?
fractional distillation
139
What is the range for bpt in crude oil?
30 ºc - 70 ºc
140
What are the names of the chemicals made in each column of fractional distillation of crude oil?
A) natural gas, refinery gas →used for cooking oil
B) gasoline, petrol → used as fuel for cars
C) naphtha → used for chemical feedstock
D) kerosene, paraffin → used as fuel for airplanes
E) diesel → used for fuel for bigger vehicles like trucks, lorries
F) fuel oil → used as fuel for boats / ships
G) lubricating oil → used for lubrication
H) bitumen → used for road surfacing
141
Describe the process of fractional distillation in crude oils
1) particles enter the column & most of them evaporate
2) some particles have a high bpt & remain liquids. these sink to the bottom of the column
3) as the particles rise through the column, they cool down and condense. **the particles condense at different heights depending on their bpt.**
4) fractions are collected as lliquids
142
Where do the smaller molecules go during fractional distillation of crude oils? Why?
the particles go to the top of the column because they have a lower bpt
143
Where do the larger molecules go during fractional distillation of crude oils? Why?
the particles go to the bottom of the column because they have a higher bpt
144
What are the conditions of crude oil when it enters the column?
temp. at 300 ºc and high pressure
