1. Which of the following can be used as a preservative for wood?
a) solvent spirit
b) petroleum coke
c) tar
d) gasoline
Explanation: Tar is used for preserving wood and the solvent spirit is mainly used for dry cleaning and as motor fuel.
2. What is the boiling range of diesel oil?
a) 120-180oC
b) 180-250oC
c) 320-400oC
d) 250-320oC
Explanation: Diesel oil’s boiling point is 250-320oC. So, in cracking the high temperatures are applied.
3. Octane number is a rating of ___________
a) petrol knocking
b) diesel knocking
c) petrol cracking
d) diesel cracking
Explanation: Octane number is the rating for petrol knocking and cetane number is the rating for diesel knocking.
4. Which of the following element has 100% anti knocking?
a) 2-methyl naphthalene
b) heptadecane
c) CH3-(-CH2-)14-CH3
d) 3-methyl naphthalene
Explanation: CH3-(-CH2-)14-CH3 has the 100% anti knocking value. It is also called as n-hexa decane. The lowest anti knocking value that is 0 is for the element 2-methyl naphthalene.
5. To improve anti knock of diesel ___________ are added.
a) TEL
b) Pre-ignition dopes
c) Di ethyl telluride
d) N-hexa decane
Explanation: To improve the anti-knock of diesel the pre-ignition dopes are added. Generally ethyl nitrate, isoamyl nitrate and acetane peroxide are added as pre-ignition dopes.
6. What are the best anti knocking reagents of petrol?
a) straight chain alkanes
b) straight chain alkenes
c) alkynes
d) aromatics
Explanation: The straight chain compounds cause maximum petrol knock and aromatics are called the best anti knock agents of petrol.
7. Pre-ignition of the fuel is seen in _________
a) petrol knocking
b) petrol cracking
c) diesel cracking
d) diesel knocking
Explanation: Petrol knocking is due to the pre-ignition of the fuel and in diesel knocking is because of ignition-lag of the fuel.
8. In liquid phase thermal cracking, the yield of petrol is ________
a) 50%-60%
b) 60%-70%
c) 70%-80%
d) 80%-90%
Explanation: In liquid phase catalytic cracking, the yield of petrol is 50-60% with good octane rating of 65-70. Here, the cracked products are sent through fractionating where the products are separated.
9. Knocking is also called as __________
a) cracking
b) pinging
c) doping
d) crushing
Explanation: Pinging is the other name of knocking. Cracking means the process of breaking the higher hydrocarbons into simple atoms. Doping means adding impurity to a pure metal to improve its conductivity. Crushing means divided into small pieces.
10. In the catalytic cracking, what Is the catalyst used?
a) Nacl
b) Kcl
c) ZnSO4
d) Al2O3
Explanation: Al2O3 and also Al2(SiO3)3 acts as catalysts in catalytic cracking. Usage of these catalysts, the quality of petrol is high without any heating.