Understanding Olefiant Gas and Ethylene

The question asks to identify the organic compound that is also known as olefiant gas and has uses in making anaesthetics, refrigerants, and various chemicals. Let's explore the history and properties of this specific gas.

Identifying Olefiant Gas

Historically, the term "olefiant gas" was used to refer to a specific gaseous hydrocarbon. This name comes from the Latin words "oleum" (oil) and "fians" (making), referring to the oily liquid formed when the gas reacts with halogens like chlorine. This characteristic reaction led chemists to coin the term.

The organic compound commonly known as olefiant gas is Ethylene.

• Ethylene is the simplest alkene, with the chemical formula \(\text{C}_2\text{H}_4\).
• It contains a carbon-carbon double bond.
• Its structure is \(\text{CH}_2=\text{CH}_2\).

Uses of Ethylene (Olefiant Gas)

As mentioned in the question, Ethylene (olefiant gas) has several important applications:

• Anaesthetics: Although less commonly used now due to flammability risks, Ethylene was historically used as an inhaled anaesthetic.
• Refrigerants: Ethylene is used as a refrigerant, particularly in cryogenic refrigeration systems.
• Chemical Production: It is a crucial building block in the petrochemical industry. It is used to produce a vast array of chemicals, including ethanol, ethylene oxide, ethylene glycol, vinyl chloride, and most significantly, polyethylene plastic.

Analyzing the Options

Let's look at why the other options are not considered olefiant gas:

• 1-Pentene: This is an alkene with five carbon atoms (\(\text{C}_5\text{H}_{10}\)) and a double bond at the first carbon. While it is an alkene and would react with halogens, the historical term "olefiant gas" specifically refers to Ethylene.
• Methane: This is the simplest alkane (\(\text{CH}_4\)). It contains only single bonds and is the primary component of natural gas. It is not an alkene and is not called olefiant gas.
• Butane: This is an alkane with four carbon atoms (\(\text{C}_4\text{H}_{10}\)). It contains only single bonds and is a major component of liquefied petroleum gas (LPG). It is not an alkene and is not called olefiant gas.

Comparing the options, Ethylene is the organic compound historically known as olefiant gas and matches the description of being used for anaesthetics, refrigerants, and other chemicals.

Conclusion

Based on the historical naming conventions and uses, Ethylene is synonymous with olefiant gas.

The correct answer is Ethylene.

Revision Table: Organic Compounds

Additional Information: Ethylene Properties

Ethylene is a simple but very important organic molecule. Understanding its properties helps explain its wide range of uses:

• It is a colorless, flammable gas with a faint sweet odor.
• The carbon-carbon double bond is a reactive functional group, making Ethylene suitable for polymerization (forming plastics like polyethylene) and other addition reactions (like reacting with halogens to form dihaloalkanes).
• Its low boiling point (\(-103.7 \, ^\circ\text{C}\)) makes it suitable for cryogenic applications.
• Ethylene is also a natural plant hormone, involved in fruit ripening and flower wilting.

The historical name "olefiant gas" highlights its reaction with halogens to form oily compounds, a characteristic reaction of alkenes, particularly Ethylene.