Chemical Technology Multiple Choice Questions on “Synthetic Organic Chemical Industries – Petrochemicals”.
1. Match the following?
Type of chemical About chemical i. Primary chemical A. Can undergoes chemical reaction ii. Intermediate chemical B. doesn’t undergo chemical change iii. End chemical C. Present in Raw material
a) i-A, ii-B, iii-C
b) i-B, ii-C, iii-A
c) i-C, ii-A, iii-B
d) i-B, ii-A, iii-C
Clarification: Primary chemicals are reasonably pure and present in raw material. Secondary chemicals are derived from primary chemicals and they can undergo chemical reaction while end chemicals cannot undergo chemical reaction.
2. Which of the following is not a primary chemical?
c) Acetic acid
Clarification: Some of the primary chemicals are Alcohol, Benzene, Toluene, and Acetone. Acetic acid is secondary chemical formed using acetylene from calcium carbide.
3. Naphtha and fuel cell produce synthesis gas by steam cracking. Is the statement true/false?
Clarification: 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.
4. Which of the following is a thermoplastic?
d) Ortho Xylene
Clarification: Polystyrene is a thermoplastic where others are feedstock type petrochemicals. Some other thermoplastics are polypropylene, PVC, HDP, low density polyethylene etc.
5. Liquefied Petroleum gas contains propane which can be cracked. Is the statement true/false?
Clarification: 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.
6. Hydro forming of petrochemical stocks doesn’t produce _______________
d) Ethyl Benzene
Clarification: Petrochemical stocks hydro forming produces BTX (toluene, benzene, Xylene) and hydrogen but not ethyl benzene. These are the principal raw materials.
7. Which of the following is a source of electrode for aluminum industry?
a) Naphtha and fuel oil
c) Petroleum coke
Clarification: Petroleum coke is a source of electrodes for aluminum electrode and it is also source of carbon for acetylene and calcium carbide. Naphtha and fuel oil, LPG, Petroleum coke are some of the principal raw materials.
8. Ethylene can be produced from ethane by ______________________
a) Catalytic cracking
b) Thermal cracking
c) Catalytic reforming
d) Hydro forming
Clarification: Ethylene of about 75% yield can be produced from ethane (4% of natural gas) by thermal cracking. Most of the ethylene is produced from refinery gases.