1. Which one of the following is a wrong statement?
a) Pressure and temperature requirements are higher for catalytic cracking
b) Rate of polymerization is increased by increasing pressure
c) Thermal pyrolysis of methane and ethane require quenching
d) Higher the molecular weight, higher is the coking tendency
Explanation: The statement is wrong as pressure and temperature requirements are lower for catalytic cracking. Gas oil undergoes catalytic cracking to produce high yield of petrol fraction.
2. Which catalyst doesn’t have high tolerance towards S when it is reactivated with steam in catalytic cracking process?
a) Iron
b) Chromium
c) Copper
d) Nickel
Explanation: Chromium doesn’t have high tolerance towards S when it is reactivated with steam in catalytic cracking process. Catalyst must be selected in such a way that it is not poisoned by metals.
3. Increase in pressure during catalytic cracking process ____________ octane number.
a) Decreases
b) Increases
c) Doesn’t effect
d) Remains same
Explanation: Increase in pressure during catalytic cracking process; decreases unsaturation and hence octane number decreases, which results in increase in coke production though reactor throughput also increases.
4. Which of the following is not a distinctive feature of catalytic cracking process?
a) Less polymerization
b) High quality petrol
c) Less coke production
d) Less Isomerization
Explanation:Distinctive features of catalytic cracking process are high quality products, selective cracking, less light ends, more Isomerization, less polymerization, and little coke.
5. Thermodynamically dehydrogenation reactions are favorable at ___________
a) High temperature, low pressure
b) Low temperature, high pressure
c) High temperature, high pressure
d) Low temperature, low pressure
Explanation: Thermodynamically dehydrogenation reactions are favorable at High temperature and low pressure. Hydro cracking and carbon deposition can occur at high temperature, hence high hydrogen pressures are used to reduce them.
6. Which of the following statement is wrong regarding Catalytic reformates?
a) They contain no olefins
b) They are resistant to oxidation
c) They have low sulfur and gum content
d) They are low in octane number
Explanation:Catalytic reformates contains no olefins, forms blending stocks, high in octane number, low in S and gum content, stable, resistant to oxidation, can make cold weather petrol due to its broad boiling point range.
7. Which of the following is not a primary chemical?
a) Alcohol
b) Acetone
c) Acetic acid
d) Benzene
Explanation: Some of the primary chemicals are Alcohol, Benzene, Toluene, and Acetone. Acetic acid is secondary chemical formed using acetylene from calcium carbide.
8. Naphtha and fuel cell produce synthesis gas by steam cracking. Is the statement true/false?
a) True
b) False
Explanation: The statement is wrong because, they produce synthesis gas but by catalytic reforming and not by steam cracking. Petrochemical starting materials are made by steam cracking from naphtha and fuel oil.
9. Which of the following is a thermoplastic?
a) Polystyrene
b) Ethylene
c) Propylene
d) Ortho Xylene
Explanation:Polystyrene is a thermoplastic where others are feedstock type petrochemicals. Some other thermoplastics are polypropylene, PVC, HDP, low density polyethylene etc.
10. Liquefied Petroleum gas contains propane which can be cracked. Is the statement true/false?
a) True
b) False
Explanation: The statement is true as LPG extracted from natural gas contains butane and propane which can be cracked into olefins. LPG can be transported in pipelines as liquid.