Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry > C9 - Crude oil and fuels > Flashcards

C9 - Crude oil and fuels Flashcards

1
Q

Where do we find Crude oil ?

A

-Crude oil is found in rocks .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of resource is crude oil ? Give the definiton .

A

Crude oil is a finite resource - if we continue to use it it will one day runout .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is Crude oil formed ?

A

-Crude oil is formed over million of years , from the remains of tiny sea creatures called plankton which were buried in mud .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Crude oil a mixture of ?

A

-Crude oil is a mixture of molecules called hydrocarbons .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are hydrocarbons ?

A

Hydrocrbons are molecules made up of only hyrdogen and carbon atoms only .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Examples of crude oil hydrocarbons .

A

Methane , Ethane , Propane and Butane .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do scientists call hydrocarbons like methane and ethane ?

A

Alkanes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Formula for Methane and draw it .

A

CH₄

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Formula for Ethane and draw it .

A

C₂H₆

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Formula for Propane and draw it .

A

C₃H₈

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Formula for Butane and draw it .

A

C₄H₁₀

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a homoglyous series ?

A

A group of compounds with similar properites that differ by CH₂

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Scientists say Alkanes are SATURATED , why ?

A

As the carbon atoms are fully bonded to hydrogen atoms in alkanes .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Meaning of Viscosity

A
  • How thick a fluid is .

- Fluids with high viscosity , flow slowly .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

As the size of hydrocarbon molecules increases , what happens to the viscosity ?

A

-The molecules become more viscous , very long chain hydrocarbons flow very slwoly - extremely viscous .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Meaning of Flammability ?

A

Tells us how easily a hydrocarbon combusts (burns).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe flammability of hydrocarbons .

A
  • Short chain hydrocarbons are extremely flammable .
  • As the size of the hydrocarbon molecules increses , the molecules become less flammable - long chain hydrocarbon are extremely difficult to burn .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Meaning of boiling point ?

A

-The temperature at which a liquid turns into a gas .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Boiling point of short chain hydrocarbons .

A

-Low boiling points
(Methane , Ethane , Propane and Butane are gases at room temperature , as their boiling points are lower than room temperarture .)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens to the boiling points as the size of the hydrocarbon molecule increases ?

A

-The boiling point also increases , very long chain hydrocarbons have very high boiling points .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What needs to be done for crude oil to be useful ?

A

-The hydrocarbons in crude oil have to be separated .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do we seaparate hydrocarbons in crude oil ?

A

Fractional distillations where crude oil is separated into fractions .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are fractions ?

A
  • Fractions contain hydrocarbons with a similar number of carbon atoms .
  • a group of compounds with simialr boiling points and chian lengths .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where does fractional distillation take place ?

A

-It takes place in very large colums found in oil refineries .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the first stage of fractional distillation of crude oil ?
-The crude oil is heated to a veyr high temperature , this causes the crude oil to boil -all the hydrocarbons evaporate and turn into gas .)
26
What is the second stage of fractional distillation of crude oil ?
-The crude oil is now fed into the fractional distillation column . The column is hotter at the bottom and cooler at the top .
27
Last few steps of fractional distillation of Crude Oil .
3. The hydrocarbon vapours now rise up the column . 4. Hydrocarbons condedse (turn back into liquid ) when they reach their boiling point . 5. Liquid fractions then removed . 6. Remaining hydrocarbons continue moving up the column , there they now condense when they reach their boiling point.
28
Where is it hto and cold in a fractional distillation collumn ?
Hot at the bottom - liquid . | Cool at the top - gas .
29
Where are long chain hydrocarbons removed in fractional distillation?
-Long chain hydrocarbons have a very high boiling point , these hydrocarbons are removed from the bottom of the column .
30
Where are short chain hydrocarbons removed in fractional distillation ?
-Very short chain hydrocarbons have very low boiling points , these do not condense , they re removed at the top of the column as gases .
31
How are some fractions used
- As fuels - petrol and diesel . | - As feedstock for the petrochemical industry .
32
What is feedstock ?
A chemical used to make other chemicals -e.g detergents .
33
Meaning of combustion
Burning
34
Meaning of Volatility
-How easily a substance turns into a gas .
35
Volatitlity of short chain hydrocarbons :
-High volatility
36
Volatility of long chain hydrocarbon :
-Low Volatility
37
How do Hydrocarbons release energy ?
-Hydrocarbons release energy when combusted (burned)
38
What happens during combustion of hydrocarbons ?
During combustion , the carbon and hydrogen atoms in the fuel react with oxyegn . The carbon and hydrogen are oxidised .
39
What happens in complete combustion ?
-The oxyegn is unlimited , this reaction produces carbondioxide and water .
40
Balance the complete bustion of propane ? | C3H8+02---> What are the products ? balance it .
Check sheet .
41
What is incomplete combusion ?
-When there is not enoguh oxyegn ot react with the fuel . Products are carbon MONOXIDE (CO) and water .
42
Products of complete combusiton :
CO2+H20 (carbon dioxide and water )
43
Products of incomplete combustion :
CO+H20 (carbon monoxide and water)
44
What is a homologous series ?
-A group of compounds with similar properties that differ by CH2 .
45
When will a liquid condense ?
-At its boiling point .
46
Why are smaller alkanes more desirable ?
-As smaller alkanes are cleaner when burnt (less smoky than large alkanes . Smaller alkanesare more easier to burn compared to large alkanes .
47
What condition is required for complete combustion to occur ?
-Plenty of oxygen for the fuel to react .
48
What condition is required for complete combusiton to occur ?
Plenty of oxygen for the fuel to react .
49
What are two key features of alkanes ?
- General formual CnH2n+2 | - ( Main one ) Alkanes only have SINGLE covalent bonds between the carbon atoms .
50
Why don't long chain hydrocarbons make good fuels , what can we do to solve this ?
- They do not as they are not flammable . - Issue is that there is a high demand for short chain hydrocarbons , so gotta convert long chain hydrocarbons into shorter ones through a process called cracking .
51
What happens during cracking ?
A long chain alkane is broken down (cracked) to produce smaller , more useful moleucles .
52
What are the products of cracking ?
-You have the short chain hydrocarbons produced but cracking also produce hydrocarbons known as ALKENES .
53
What are the two ways that can be used for cracking ?
- Catalytic Cracking | - Steam Craking .
54
How does catalytic cracking work ?
-In catalytic cracking , we use high temperature and catalysts which speed up the reaction .
55
How does steam cracking work ?
-In steam cracking you use , steam and high temperature .
56
What bonds do alkenes have ?
-Alkenes have DOUBLE covalent bonds between two carbon atoms (unlike alkanes) .
57
Alkenes are useful molecules , how can they be used ?
- They are used to make chemicals called polymers . | - Alkenes are also used as the starting material for other useful chemicals as well .
58
Reactvity of alkenes .
Alkenes are MORE REACTIVE than alkanes . Can use this to test for alkenes .
59
What is the test for alkenes ?
-We test for alkenes using bromine water which is orange . -Of we shake our alkene with bromine water . -The bromine water turns colourless . VERY IMPORTANT YOU SAY COLOURLESS NOT CLEAR IN EXAM ..
60
do some balance equations for cracking
(check sheet if stuck )
61
What is the MOLECULAR formula of ethene ?
C2H4
62
What is the displayed formula , what is the displayed formul of ethene ?
The displayed formula shows us all the atoms and the covalent bonds .Check sheet .
63
What is the general formula for alkenes ?
C2H2n - If we know the number of carbon atoms (n) , we can calculate the number of hydrogen atoms by X2 the number of carbon atoms .
64
Where can you put double bonds in alkenees ?
-In GCSE between any two adjacent carbon atoms .
65
What four alkenes do you need to know ? Write the molecular formula for theemm and the displaed formula .
-Ethene -Propene -Butene -Pentene Check seet for answers .
66
Why do scientists say that alkene molecules are unsaturated ?
-As alkenes have two fewer hydrogen atoms than the alkane with same number of carbon atoms . ETHANE has six hydrogens but ETHENE has four hydrogens , they both have same number of carbon atoms .
67
Why do all alkenes react in a similar way ?
As all alkenes have a double bond .
68
What do scientists call the double bond in alkenes ?
-The Alkene functional group .
69
What is the meaning of a "functional group"
The part of the molecule that determines how it reacts . | -All alkenes have the same fuctional grup (carbon co carbon double bond.)
70
Scientists call molecules like alkenes a homologous series , what does that mean ?
- Molecules of a homologous series has the same fuctionl group and the same formula and difer by CH2 - Each molecule in the homologouse series has an extra carbona tom and two extra hydrogen atoms /
71
What are the products of the combustion of alkenes ?
-Produce carbondioxide and ater like alkanes . -However , incomplete combustion of an alkene also produces unburnt carbon paerixles , this is because of incomplete combstion . As a result , alkenes burn in air with a smoky flame .
72
What are the requirements of hydrogenation ?
- This reaction requires a temperature of around 150 degrees . - Also requires a nickel catlayst to speed up the reaction .
73
How are the hydrogen atoms added in hydrogenation ?
- The two hydrogen atoms are added across the double bond . | - The carbon to carbon double bond is converrted ino a carbon to carbon single bond .
74
What happened to the hydrogenaiton reactionn ont he page . | So what does reacitng an alkene with hydrogen produce ?
- It converted ethene into the alkane ethane . | - Reacting an alkene with hydrogen produces an alkane .
75
-What fractions of crude oil are usually cracked
Naptha
76
-Why are they cracked
-To rpoduce moe useful and shorter chain alkanes .
77
-What type of reaction is cracking ?
-Thermal decompostion - when a compound breaks down when heated .
78
What are the two products formed in cracking ?
- Short chain alkane | - alkene .
79
meaning of combustion (burning)
-The reaction of something with oxygen .
80
Give for useful products from fractional distillatio .
- Solvents - Lubricating oils - Fuels - Detergents

Chemistry (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions