Essential Chemistry for IGCSE - Organic Chemistry And Petrochemicals (Section 2)
1
What is the general trend of boiling points within a homologous series?
Answer
(B)
Boiling points increase with chain length.
2
Which fraction of crude oil would be most useful as a lubricant?
Answer
(D)
Fuel Oil
3
What are the products of complete combustion of any hydrocarbon?
Answer
A
B
4
Which two factors influence the flammability of fuels?
Answer
A
C
5
Which of the following statements about the combustion of hydrocarbons is/are correct?
Answer
A
D
6
What is the role of a catalyst in cracking hydrocarbons?
Answer
(B)
To speed up the reaction.
7
What is the relationship between the number of carbon atoms and the volatility of alkanes?
Answer
(B)
Volatility decreases with an increasing number of carbon atoms.
8
Which of the following properties generally decreases as the number of carbon atoms in an alkane molecule increases?
Answer
(C)
Flammability
9
What is the primary source from which most petrochemicals are derived?
Answer
(C)
Crude Oil
10
Which of the following statements is TRUE regarding the properties of hydrocarbons in the same homologous series as the number of carbon atoms increases?
Answer
(C)
Viscosity increases.
11
What type of bonds are found in alkanes?
Answer
(A)
Single covalent bonds
12
Which of the following is a primary environmental problem associated with the combustion of fossil fuels?
Answer
(B)
Greenhouse effect
13
Which of the following is a characteristic of a good fuel?
Answer
(A)
Releases a large amount of energy per gram.
14
What is the name of the process used to break down large hydrocarbons into smaller, more useful molecules?
Answer
(C)
Cracking
15
What process is used to separate crude oil into fractions?
Answer
(B)
Fractional distillation
16
Which of the following is an advantage of using hydrogen as fuel?
Answer
(B)
It produces water as the only product.
17
Which of the following best describes the relationship between the number of carbon atoms and the ease of combustion in hydrocarbons?
Answer
(B)
As the number of carbon atoms increases, the ease of combustion decreases.
18
Which of the following best describes the trend of viscosity as the number of carbon atoms increases in a homologous series of alkanes?
Answer
(B)
Viscosity increases.
19
Which of the following fractions from crude oil is most viscous at room temperature?
Answer
(D)
Bitumen
20
What is the key characteristic that allows fractional distillation to separate hydrocarbons?
Answer
(B)
Boiling point differences
21
Which of the following is the main difference between a fuel and a lubricant?
Answer
(B)
A fuel is burned; a lubricant reduces friction.
22
Which of the following is the role of the fractionating column in fractional distillation?
Answer
(B)
To separate crude oil into fractions based on boiling points.
23
What is the functional group present in alcohols?
Answer
(B)
-OH
24
Which type of crude oil fraction is used for lubricants?
Answer
(D)
Lubricating oils
25
Which homologous series is characterized by the presence of a carbon-carbon double bond?
Answer
(B)
Alkenes
26
Which of the following are true for complete combustion?
Answer
A
B
C
27
Which of the following fractions from the fractional distillation of crude oil has the lowest boiling point?
Answer
(C)
Gasoline
28
Which of the following is not a feature of a homologous series?
Answer
(D)
Same physical properties.
29
Which of the following factors would NOT affect the flammability of a hydrocarbon?
Answer
(C)
The presence of oxygen in the molecule.
30
Which of the following is the correct order of fractions obtained from fractional distillation of crude oil, from the top to the bottom of the fractionating column?
