Organic Chemistry F. The Fuel

31. The stench due to leakage from LPG cylinder is because of – [U.P.P.C.S. (Pre) 2017]

(a) Methane
(b) Propane
(c) Butane
(d) Ethyl mercaptan

Correct Answer: (d) Ethyl mercaptan

Solution:Liquefied Petroleum Gas (LPG) is a flammable mixture of hydrocarbon gases which is used as fuel. LPG is a mixture of butane and propane. LPG is an odourless gas product. However, to identify the leakage ethyl mercaptan is used in LPG.

32. Match items in the List-I with List-II and select the correct answer using the codes given below the lists: [R.A.S./R.T.S. (Pre) 2013]

List-I (Fuel Gases) List-II (Major Constituents)
A. CNG i. Carbon monoxide, Hydrogen
B. LPG ii. Butane, Propane
C. Coal gas iii. Methane, Ethane
D. Water gas iv. Hydrogen, Methane, Carbon monoxide

List-I (Fuel Gases) List-II (Major Constituents)

CNG: iii. Methane, Ethane

LPG: ii. Butane, Propane

Coal gas: iv. Hydrogen, Methane, Carbon monoxide

Water gas: i. Carbon monoxide, Hydrogen

(a) ii iv iii i
(b) iii iv ii i
(c) iii ii iv i
(d) iii ii i iv

Correct Answer: (c) iii ii iv i

Solution:The correctly matched lists are as follows:

CNG: Methane, Ethane
LPG: Butane, Propane
Coal gas: Hydrogen, Methane, Carbon monoxide
Water gas: Carbon monoxide, Hydrogen

33. Assertion (A): The main component of the liquefied petroleum gas is methane. [I.A.S. (Pre) 2005]

Reason (R): Methane can be used directly for burning in homes and factories where it can be supplied through pipelines.

(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

Correct Answer: (d) (A) is false, but (R) is true.

Solution:The Assertion (A) of the given question is wrong, while the reason (R) is correct. The main components of L.P.G. are propane and butane. Methane, present in biogas, can be used directly as a fuel. LPG is the abbreviation of Liquefied Petroleum Gas. Like all fossil fuels, it is a non-renewable source of energy. It is extracted from crude oil and natural gas. The main composition of LPG are hydrocarbons containing three or four carbon atoms.

34. The Pressure gauge is not given in the domestic LPG cylinders because – [42nd B.P.S.C. (Pre) 1997]

(a) They are so costly
(b) They cannot represent the quantity of gas in LPG cylinders
(c) Their use is not safe
(d) They are choked by LPGs

Correct Answer: (b) They cannot represent the quantity of gas in LPG cylinders

Solution:Oxygen and other gases found in the gas cylinders are in a gaseous state, while in domestic LPG cylinders, gas is found in the liquid state. So, the pressure gauge cannot represent the quantity of gas in LPG cylinders. That is why the pressure gauge is not given in the domestic LPG cylinders.

35. In what form cooking gas is supplied in cylinders? [Uttarakhand Lower Sub. (Pre) 2010]

(a) Liquid
(b) Gas
(c) Solid
(d) Solution

Correct Answer: (a) Liquid

Solution:Oxygen and other gases found in the gas cylinders are in a gaseous state, while in domestic LPG cylinders, gas is found in the liquid state. So, the pressure gauge cannot represent the quantity of gas in LPG cylinders. That is why the pressure gauge is not given in the domestic LPG cylinders.

36. Which among the following compounds is the main constituent of natural gas? [U.P. P.C.S. (Pre) 2012]

(a) Hexane
(b) Methane
(c) Butane
(d) Benzene

Correct Answer: (b) Methane

Solution:Natural gas is an odorless, gaseous mixture of hydrocarbons, predominantly made up of methane (CH₄) in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Two forms of natural gas are currently used in vehicles and for cooking: compressed natural gas (CNG) and liquefied natural gas (LNG). Natural gas, extracted from below Earth's surface, is processed and converted to CNG and

37. Which is the main component of natural gas? [Chhattisgarh P.C.S. (Pre) 2016]

Correct Answer: (a) Methane

Solution:

Natural gas is an odorless, gaseous mixture of hydrocarbons, predominantly made up of methane (CH₄) in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Two forms of natural gas are currently used in vehicles and for cooking: compressed natural gas (CNG) and liquefied natural gas (LNG). Natural gas, extracted from below Earth's surface, is processed and converted to CNG and LNG.

38. CNG is – [U.P.P.C.S. (Pre) 2015]

(a) Compressed Natural Gas
(b) Cyanogen Natural Gas
(c) Condensed Nitrogen Gas
(d) Controlled Natural Gas

Correct Answer: (a) Compressed Natural Gas

Solution:C.N.G. is the short form of Compressed Natural Gas. It is a readily available alternative to gasoline which is made by compressing natural gas to less than 1% of its volume standard atmospheric pressure.

39. CNG used in automobiles to check pollution mainly consists of - [U.P.P.C.S. (Pre) 2005]

(a) CH₄
(b) CO₂
(c) N₂
(d) H₂

Correct Answer: (a) CH₄

Solution:CNG is made by compressed natural gas which is mainly composed of methane (CH₄). It is a mixture of hydrocarbons, which is found deep inside Earth and has approx. 80% to 90% of methane.

40. The major component of CNG is - [66th B.P.S.C. (Pre) (Re. Exam) 2020]

(a) CO₂
(b) N₂
(c) H₂
(d) CH₄

Correct Answer: (d) CH₄