Petroleum and Oil Refining

Multiple Choice Quiz

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At a refinery, crude oil is separated into its components by
1. fractional distillation
2. filtration
3. decanting
4. catalytic cracking
The fraction of crude oil which has less than four carbon atoms per molecule is called
1. refinery gas
2. kerosene
3. naphtha
4. gas oil
The fraction of crude oil used in petrol is
1. light gasoline
2. kerosene
3. gas oil
4. fuel oil
The fraction of crude oil that is used in LPG (liquid petroleum gas) is
1. refinery gas
2. naphtha
3. gas oil
4. residue
Study the diagram of the fractionating column.
What fractions come out at X and Y? $fractionating.png$
1. X = refinery gas and Y = gas oil
2. X = refinery gas and Y = light gasoline
3. X = kerosene and Y = refinery gas
4. X = residue and Y = gas oil
From which fraction of crude oil are central heating fuel and jet fuel obtained?
1. Kerosene
2. Refinery gas
3. Light gasoline
4. Residue
When crude oil is heated and passed through a fractionating column, the different fractions separate out according to their
1. boiling points
2. melting points
3. densities
4. colours
The main constituent of natural gas is methane. From the list below, select two other gases that make up natural gas.
1. Ethane
2. Propane
3. Ethyne
4. 2,2,4-dimethylpentane
5. Methylbenzene
Why are mercaptans added to natural gas?
1. To give natural gas a smell so that leaks may be detected.
2. To make it burn more efficiently
3. In order that it may be more easily stored.
4. To increase its octane number.
Damage may be caused to the internal combustion engine by premature ignition of the fuel:air mixture. Premature ignition may also be expressed by three other terms.
Select these three terms from the list below.
1. Auto-ignition
2. Knocking
3. Pinking
4. Injection
The measure of the tendency of a fuel to prematurely ignite is measured by its
1. octane number
2. fuel number
3. number of carbon atoms
4. relative molecular mass
The octane number is a measure of a fuel's tendency to auto-ignite. In fixing a scale of octane numbers from 0 to 100, two compounds were chosen and assigned numbers 0 and 100.
These two compounds respectively are:
1. heptane and 2,2,4-trimethylpentane
2. heptane and octane
3. octane and 2,2,4-trimethylpentane
4. propane and 2,2-dimethylpentane
Premature ignition in a petrol engine is prevented by which two of the following:
1. Use of additives
2. Use of high octane compounds
3. Use of leaded petrol
4. Use of a low octane compound
To prevent knocking in petrol engines, compounds called oxygenates are added to the petrol.
Which one of the following is NOT considered an oxygenate?
1. Octane
2. Ethanol
3. MTBE
4. Ether
High-octane compounds are used to prevent knocking in petrol engines.
Which one of the following features is not present in high-octane compounds?
1. Presence of C=C bonds.
2. High degree of branching
3. Short chain length
4. Presence of one or more ring structures
Low-octane compounds may be converted into more desireable high-octane compounds by which THREE of the following processes?
1. Isomerisation
2. Dehydrocyclisation
3. Catalytic cracking
4. Knocking
Catalytic cracking involves taking a heavy oil and heating it to a high temperature in the presence of a catalyst.
Select three advantages of cracking from the list below:
1. Useless, long-chain compounds are converted into more useful shorter chain compounds.
2. High-octane, branched chain alkenes are made which are suitable for petrol.
3. Alkenes, suitable for the manufacture of polymers are made.
4. Hydrogen gas, used in making ammonia is produced.
Which one of the following is NOT a property of hydrogen gas?
1. It is a very dense gas.
2. It is a colourless gas.
3. It is almost insoluble in water.
4. It is an odourless gas.
Which one of the following is not a use of hydrogen gas?
1. Preparation of ethyne gas
2. Manufacture of ammonia
3. Hydrogenation of vegetable oils
4. Manufacture of hydrochloric acid
Hydrogen is obtained from methane by a process called
1. steam reforming
2. hydrogenation
3. isomerisation
4. catalytic cracking
Butane is a major component of LPG.
What does LPG stand for?
1. Liquid petroleum gas
2. Low petrol gas
3. Liquid plastic gas
4. Light Petroleum gas
What two structural features of 2,2,4-trimethylpentane results in it having a high octane rating?
1. It has three methyl branches.
2. It has a short chain
3. It is saturated.
4. It doe not contain oxygen atoms.
Lead compounds were used in the past to increase the octane number of fuels.
Why are lead compounds unsuitable as additives for petrol in modern cars?
1. Lead compounds poison the metal catalyst in the catalytic converter of the car.
2. Lead is a very expensive metal.
3. Lead compounds are not very soluble in petrol.
4. Lead compounds in petrol reduce the speed of cars.
The table shows the octane numbers of some hydrocarbons.
Hexane has the lowest octane number of the four compounds listed.
What structural feature of hexane contributes to this?
1. Hexane has a straight chain.
2. Hexane contains a ring structure.
3. It does not contain lead.
4. It does not contain oxygen.
The table shows the octane numbers of some hydrocarbons.
Benzene has the highest octane number of the four compounds listed.
What structural feature of benzene contributes to this?
1. It contains a ring structure.
2. It has a long chain.
3. It has branches along the molecule.
4. It contains oxygenates.
Oxygenates are added to petrol.
Why is this?
1. To increase the octane number of the petrol.
2. To cause catalytic cracking.
3. To decrease the toxicity of the petrol.
4. To make the petrol less flammable.
Which one of the following is NOT a reason for using methyl tert-butyl ether (MTBE) in the petrochemical industry?
1. To help crack long chain hydrocarbons.
2. To increase the oxidation number of a fuel.
3. To prevent knocking in a petrol engine.
4. To reduce pollution.
In which fraction of crude oil does pentane and its isomers occur?
1. Light gasoline (petrol)
2. Gas oil
3. Naphtha
4. Fuel oil
Which one of the following has the lowest octane number?
Naphtha and gas oil are two of the hydrocarbon fractions obtained from the fractional distillation of crude oil.
How do the molecules of the naphtha fraction differ from the molecules of the gas oil fraction?
1. Naphtha molecules are smaller than gas oil molecules.
2. Naphtha molecules have greater densities than gas oil molecules.
3. Naphtha molecules have lower boiling points.
4. Gas molecules have higher boiling points.
Name the fractions X and Y which are separated in the fractional distillation of crude oil. $fract_column23a.png$
1. X = light gasoline, Y = gas oil
2. X = light gasoline, Y = residue
3. X = naphtha, Y = kerosene
4. X = kerosene, Y = gas oil
Crude oil is separated into a number of fractions.
Select two fractions which contain molecules with their carbon lengths suitable for petrol?
1. Light gasoline
2. Naphtha
3. Bitumen
4. Gas oil
Which one of the following is a use of the kerosene fraction obtained when crude oil is fractionated?
1. Aviation fuel
2. Liquid petroleum gas
3. Petrol
4. Lubricating oil
The straight chain molecule C₁₃H₂₈ occurs in the kerosene fraction.
When this molecule is cracked, a C₂H₄ molecule, a C₄H₈ molecule and an unbranched alkane molecule are obtained.
What is the unbranched alkane molecule, what is its octane number?
1. C₇H₁₆ and an octane number of 0
2. C₇H₁₄ and an octane number of 100
3. C₅H₁₀ and an octane number of 0
4. C₆H₁₄ and an octane number of 75
What two processes are carried out in oil refineries to modify the octane number of hydrocarbons?
1. Isomerisation and dehydrocyclisation
2. Catalytic cracking and dehydrocyclisation
3. Isomerisation and Electrolysis
4. Electrolysis and catalytic cracking
What is the major use for the light gasoline and naphtha fractions of crude oil?
1. Petrol/motor fuel
2. Bitumen
3. Diesel fuel
4. Liquid petroleum gas
Which one of the following is NOT a use of catalytic cracking?
1. Produces hydrogen gas
2. Gives more useful products
3. Gives products with high octane numbers
4. Gives products needed for petrol
State one disadvantage of using hydrogen as a fuel.
1. It is difficult to store.
2. There is no pollution from burning hydrogen.
3. Burning it does not produce carbon dioxide.
4. Hydrogen fuel cells are very efficient.
In the fractionating column shown, what fractions come out at A and B?
1. Light gasoline at A and naphtha at B
2. Naphtha at A and lubricating oil at B
3. Gas oil at A and naphtha at B
4. Residue at A and kerosene at B
In the fractionating column shown, what fractions come out at X and W?
1. X = bitumen and W = petrol
2. X = petrol and W = bitumen
3. X = petrol and W = diesel
4. X = naphtha and W = bitumen
Which one of the following is not a refinery process?
1. Reduction
2. Fractionation.
3. Cracking
4. Reforming.
When a saturated alkane is cracked
1. one or more of the products must be unsaturated.
2. all products are saturated.
3. there are always just two products.
4. there must be at least one branched product.
Which one of the following methods does NOT lead to an increase in the octane number of petrol?
1. Neutralisation
2. Isomerisation
3. Reforming
4. Adding oxygenates
The breaking down of a long chain hydrocarbon molecules into short chain molecules is known as
1. catalytic cracking.
2. nuclear fission.
3. isomerisation
4. knocking.
Which one of the following is NOT a factor affecting the octane number of a fuel?
1. The addition of a catalyst to the fuel.
2. The length of the alkane chain.
3. The amount of branching in the chain.
4. The presence of a cyclic structure in a hydrocarbon gives it a higher octane number.
The naphtha fraction of crude oil is used mainly
1. as a source of medicines, plastics and detergents.
2. as aviation fuel.
3. as lubricating oil in engines.
4. in waterproofing and roofing.
Which one of the following fractions of crude oil has the longest chain of carbon atoms?
1. Fuel oil
2. Diesel oil
3. Petrol
4. Refinery gas
Which one of the following types of compound is added to natural gas (methane) in order to detect a leakage of that gas?
1. Mercaptans
2. Esters
3. Catalysts
4. Naphtha