Cracking Flashcards
What is cracking in chemistry?
Cracking is the process of breaking down larger hydrocarbon molecules into smaller, more useful molecules.
True or False: Cracking is used to produce heavier hydrocarbons.
False
What are the two main types of cracking?
Thermal cracking and catalytic cracking.
Fill in the blank: The main feedstock for cracking is _______.
crude oil
What is the primary product of cracking?
Alkanes and alkenes.
Which type of cracking involves high temperatures and pressures?
Thermal cracking.
What is the role of a catalyst in catalytic cracking?
To lower the activation energy and increase the rate of reaction.
What is the typical temperature range for thermal cracking?
450 to 750 degrees Celsius.
True or False: Alkenes are more reactive than alkanes.
True
What is the main advantage of catalytic cracking over thermal cracking?
It produces a higher yield of gasoline and lower molecular weight hydrocarbons.
What type of hydrocarbon is primarily produced from cracking processes?
Short-chain hydrocarbons.
Multiple Choice: Which of the following is NOT a product of cracking? A) Ethylene B) Propane C) Octane D) Methanol
D) Methanol
What are the environmental concerns associated with cracking?
Air pollution and greenhouse gas emissions.
True or False: Cracking can be used to produce fuel for vehicles.
True
What is the significance of the cracking process in the petroleum industry?
It helps meet the demand for lighter fuels and petrochemicals.
What is the process called that converts alkenes back into alkanes?
Hydrogenation.
Fill in the blank: The presence of ______ helps to facilitate catalytic cracking.
a catalyst
What is the purpose of using a zeolite catalyst in catalytic cracking?
To enhance selectivity and yield of desired products.
What is the difference between saturated and unsaturated hydrocarbons?
Saturated hydrocarbons contain only single bonds, while unsaturated hydrocarbons contain double or triple bonds.
Multiple Choice: Which product is primarily used for making plastics? A) Ethylene B) Octane C) Methanol D) Hexane
A) Ethylene
What is the main characteristic of alkenes that makes them reactive?
The presence of a carbon-carbon double bond.
True or False: Alkenes can undergo addition reactions.
True
What is the general formula for alkenes?
CnH2n.
What type of reaction is cracking classified as?
A decomposition reaction.
What is the main byproduct of the cracking process?
Soot and other hydrocarbons.
Fill in the blank: Catalytic cracking primarily occurs in a _______.
fluidized bed reactor
What is a common use for the products obtained from cracking?
Fuel for cars and as feedstock for chemical synthesis.
What is the effect of temperature on the yield of products from cracking?
Higher temperatures generally increase the yield of smaller hydrocarbons.
True or False: Cracking is an endothermic reaction.
True
What is the role of steam in steam cracking?
To help break down the hydrocarbons and increase yields of lighter products.
Multiple Choice: Which of the following is a common catalyst used in catalytic cracking? A) Nickel B) Platinum C) Copper D) Iron
B) Platinum
