Worksheet: Cracking of Hydrocarbons

In this worksheet, we will practice describing the uses of alkenes and writing balanced equations for their production by catalytic cracking of alkanes.

Q1:

Which type of chemical reaction is cracking an example of?

  • AAddition
  • BHydrolysis
  • CCondensation
  • DDecomposition
  • EDisplacement

Q2:

The cracking of a nonane molecule can produce a range of products.

If the cracking of a nonane molecule produces two molecules including propene, what is the name of the second product?

  • AHexene
  • BPentane
  • CPentene
  • DHexane
  • EHeptene

Which of the following pairs of molecules can be produced by the cracking of a nonane molecule, assuming there are no other products?

  • AButane + pentene
  • BOctane + methane
  • CHexene + propene
  • DPropane + heptene
  • EEthene + hexene

Which of the following groups of molecules can be produced by the cracking of a nonane molecule, assuming there are no other products?

  • APropene + propene + propene
  • BEthene + ethane + pentane
  • CPropane + ethene + butene
  • DHexene + propane + ethene
  • EButene + propane + methane

Q3:

Which of the following statements is true?

  • ACracking is a method of polymerization.
  • BCracking increases the chain length of the hydrocarbon.
  • CCracking is exothermic.
  • DCracking is possible without a catalyst.
  • ECracking always generates gaseous products.

Q4:

In which of the following properties is an increase observed when hydrocarbon fuels undergo cracking?

  • AMelting point
  • BMolecular size
  • CViscosity
  • DVolatility
  • EIgnition temperature

Q5:

In catalytic cracking, a gaseous hydrocarbon flows over a heated catalyst and is converted to more valuable products. Which of the following catalyst properties cannot be increased to produce a higher reaction rate?

  • A Surface area
  • B Porosity
  • C Mass
  • D Particle size
  • E Temperature

Q6:

Cracking may be used to convert one fraction of crude oil to a mixture of hydrocarbons with the properties of a different fraction. Which of the following fuels can be replicated via the cracking of kerosene?

  • ADiesel oil and gasoline
  • BGasoline only
  • CLPG only
  • DGasoline and LPG
  • EDiesel oil, gasoline, and LPG

Q7:

In which range of temperatures is catalytic cracking usually performed?

  • A 1 0 0 3 0 0 C
  • B 0 1 0 0 C
  • C 3 0 0 5 0 0 C
  • D 5 0 0 7 0 0 C
  • E 7 0 0 9 0 0 C

Q8:

A hydrocarbon has the structural formula shown:

The cracking of this hydrocarbon can produce a range of products.

What is the molecular formula of this hydrocarbon?

  • A C H 1 0 2 0
  • B C H 8 1 8
  • C C H 1 0 2 2
  • D C H 8 1 6
  • E C H 9 1 8

What are the structural formulas of the products when one molecule of this hydrocarbon undergoes a single cracking reaction?

  • A
  • B
  • C
  • D
  • E

Q9:

Hydrocarbons X and Y are produced by cracking decane ( C H ) 1 0 2 2 . The molecular formula of X is C H 6 1 2 .

What is the molecular formula of Y ?

  • A C H 6 1 0
  • B C H 4 8
  • C C H 5 1 0
  • D C H 4 1 0
  • E C H 6 1 4

Which diagram illustrates the appearance of a glowing splint after exposure to the vapor of compound X in air?

  • A
  • B
  • C
  • D
  • E

Which diagram illustrates a test tube of bromine water after the addition of a large quantity of compound X ?

  • A
  • B
  • C
  • D
  • E

Which diagram illustrates a test tube of potassium permanganate solution after the addition of a large quantity of compound Y ?

  • A
  • B
  • C
  • D
  • E

Q10:

Under which of the following conditions is thermal cracking usually performed?

  • ALow temperature and high pressure
  • BHigh temperature and low pressure
  • CLow temperature and low pressure
  • DHigh temperature and high pressure

Q11:

An alkane undergoes three different cracking reactions to produce a range of compounds, as shown by the equations.

At room temperature and pressure, compounds W , Y , and Z are gases and compound X is a liquid. The results of testing the compounds with bromine water are shown in the diagram.

B r 2 ( aq ) X Z W Y X Z W Y

What is the displayed formula of compound W ?

  • A
    C H C H C H H H C H H H
  • B
  • C
  • D
  • E

What is the displayed formula of compound X ?

  • A
  • B
  • C
  • D
  • E

What is the displayed formula of compound Y ?

  • A
  • B
  • C
  • D
  • E

What is the displayed formula of compound Z ?

  • A
  • B
  • C
  • D
  • E

Q12:

Shown in the equation is one possible reaction in the cracking of heptane:

+ X C H H H C H C H C H H H H C C H H C H H H H H C H C H H H C H H

Compound X is an unbranched hydrocarbon. What is the displayed formula of compound X ?

  • A
    C H C H H H C H H C H H H C H H H
  • B
    C H C H C H H C H H H H
  • C
    C H H H C C H H H H H
  • D
    C H C H H H H C C H H H H H
  • E
    C C H C H H C H H H H H C H H

Q13:

Cracking of compound X produces smaller molecules according to the equation shown:

Compound X is an unbranched hydrocarbon. What is the displayed formula of compound X ?

  • A
  • B
  • C
  • D
  • E

Q14:

During catalytic cracking of a hydrocarbon mixture, a molecule X reacts according to the equation shown:

Which of the following is a possible structural formula for the reacting molecule?

  • A
  • B
  • C
  • D
  • E

Q15:

In a cracking reaction, a hydrocarbon with molecular formula C H 1 8 3 8 is converted to two liquid compounds A and B . The displayed formula of A is as shown: