Note: This whole section is a part of Forensic Chemistry MCQs that includes topics such are arson, petroleum, and explosive products. These are made specifically for the preparation of NTA UGC NET and University entrance tests.
1. In crude oil, which one of the non-hydrocarbon elements is most abundant?
- Oxygen
- Sulphur
- Nitrogen
- Helium
Answer and Explanation
Answer: (1) Oxygen
Explanation: -> Crude oil is composed of hydrocarbons such as:
● Hydrogen (about 13%)
● Carbon (about 85%).
-> Non-hydrocarbon elements are:
● Nitrogen (about 0.5%)
● Sulfur (0.5%)
● Oxygen (1%
2. Which of the following is not a petroleum product?
- Bitumen
- Wax
- Petrol
- TATP
Answer and Explanation
Answer: (4) TATP
Explanation: Triacetone triperoxide (TATP) is a highly unstable explosive.
3. To meet the Euro II requirement, the lead contents in gasoline should be
- 0.013 gm/lt
- 0.005 gm/lt
- 0.05 gm/lt
- 0.5 gm/lt
Answer and Explanation
Answer: (2) 0.005 gm/lt
Explanation: European Emission standards define the acceptable limits for the exhaust emissions of new vehicles that are sold in the European Union and EEA member states.
-> The Euro 2 standard defines the value to limit carbon monoxide emissions from the combined limit for unburned hydrocarbons and oxides of nitrogen for both petrol and diesel vehicles.
4. Adulteration of gasoline with Kerosene oil can be detected by:
- TLC
- GLC
- HPLC
- HPTLC
Answer and Explanation
Answer: (2) GLC
Explanation: Read More: Detection of Adulteration in Petrol Using Gas Chromatographic Technique
5. Kerosene is a blend of:
- Paraffins
- Naphthenes
- Aromatics
- All of the above
Answer and Explanation
Answer: (4) All of the above
Explanation: Apart from paraffin, naphthenes, and aromatics, a blue color dye is also added— 1-4-dialkyl-amino-anthraquinone dye to prevent the use of kerosene as an adulterant.
6. Petroleum products include:
- LPG and CNG
- Aviation spirit
- Kerosene
- All of the above
Answer and Explanation
Answer: (4) All of the above
7. Which of the following is used to color motor gasoline?
- Phenyl azo-2-naphthol
- Eosine
- Di-alkyl amino anthraquinone
- Erythrosine
Answer and Explanation
Answer: (1) Phenyl azo-2-naphthol
Explanation: 4′-hydroxy-1-phenyl azo-2-naphthol is a metabolite of Sudan I. Sudan I is an organic compound that is an azo dye that gives an intense orange-red color to the various petroleum substance such as waxes, oils, petrol, solvents, and polishes. (Source)
8. The important characteristic of petrol includes:
- Anti-knock index
- Density
- Research octane number
- All of the above
Answer and Explanation
Answer: (4) All of the above
9. Domestic kerosene is blue in color due to
- Anthracene
- Coomassie Blue
- Solvent Blue 35
- Eosine
Answer and Explanation
Answer: (3) Solvent Blue 35
Explanation: The common dye component of kerosene is 1-4-dialkyl-amino-anthraquinone that is responsible for kerosene’s blue color.
-> Common variants of anthraquinone dyes used in kerosene are:
● Solvent Green 33
● Solvent Blue 35
● Solvent Blue 26
Reference: Fuel Dyes
10. Blue color of PDS kerosene is due to the presence of which dye?
- Phenyl azo-naphthol
- Dialkyl amino anthraquinone
- Anthraquinone
- Anthracene
Answer and Explanation
Answer: (2) Dialkyl amino anthraquinone
Explanation: Blue color of Public Distribution System (PDS) kerosene is due to the presence of 1-4-dialkyl-amino-anthraquinone dyes which is useful in distinguishing it as a subsidized product and also to detect the adulteration in other costly petroleum products.
11. Dye component of kerosene can be analyzed by
- GC
- AES
- XRF
- TLC
Answer and Explanation
Answer: (4) TLC
Explanation: The common dye component of kerosene is 1-4-dialkyl-amino-anthraquinone that is responsible for kerosene’s blue color.
12. The furnace oil or black oil consists of hydrocarbons above:
- C20
- C30
- C40
- C50
Answer and Explanation
Answer: (3) C40
13. Typical standard kerosene has a relative density of ________ at 15 °C.
- 0.68 to 0.70
- 0.78 to 0.82
- 0.82 to 0.87
- 0.90 to 0.92
Answer and Explanation
Answer: (2) 0.78 to 0.82
Explanation: The relative density of standard kerosene oil is 0.78–0.81 g/cm3 at 15 °C.
14. The following percentage of cooking gas forms an explosive mixture with air
- 2-7%
- 13-17%
- 20-27%
- 28-30%
Answer and Explanation
Answer: (1) 2-7%
Explanation: Talking in general, the cooking gas cylinder doesn’t explode till the gas level in-cylinder reaches 1.4% to 7.6% gas to air ratio.
15. Kerosene normally boils in the range of:
- 350 °C – 450 °C
- 150 °C – 250 °C
- 750 °C – 850 °C
- 550 °C – 650 °C
Answer and Explanation
Answer: (2) 150 °C – 250 °C
Explanation: Other fuel along with their boiling point:
-> n-Octane: 125.72 °C
-> n-Hexane: 68.72 °C
-> Petrol: 25 to 210 °C
-> Diesel: 180–360 °C
Please note: Petrol is the blend of C4 to C11 hydrocarbons that’s the reason why they have a boiling point ranging from 25 and 210°C.
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