Understanding Laughing Gas

The question asks to identify the substance commonly known as 'Laughing Gas'. This substance is a chemical compound with specific properties.

What is Laughing Gas?

'Laughing Gas' is the common name for a chemical compound. Let's look at the options provided:

1. Hydrogen Peroxide ($\text{H}_2\text{O}_2$)
2. Nitrous Oxide ($\text{N}_2\text{O}$)
3. Carbon Monoxide ($\text{CO}$)
4. Sulphur Dioxide ($\text{SO}_2$)

Out of these options, Nitrous Oxide ($\text{N}_2\text{O}$) is the chemical compound that is widely recognized as Laughing Gas.

Properties and Uses of Nitrous Oxide

Nitrous Oxide is a colorless, non-flammable gas at room temperature. It has a slightly sweet odor and taste. It is used in various applications, including:

• As an anesthetic and analgesic (pain reducer) in medicine and dentistry.
• As a propellant in aerosol cans.
• In internal combustion engines to increase power output (often called "nitrous" in racing).

It is called 'Laughing Gas' because inhaling it can cause euphoria and sometimes slight hallucinations or uncontrollable laughter. This is due to its effects on the nervous system.

Why Other Options Are Incorrect

• Hydrogen Peroxide ($\text{H}_2\text{O}_2$): This is a liquid primarily known for its use as a disinfectant and bleach. It is not a gas and is not known as Laughing Gas.
• Carbon Monoxide ($\text{CO}$): This is a highly toxic, colorless, and odorless gas produced by incomplete combustion. It is a dangerous poison and has no connection to the term 'Laughing Gas'.
• Sulphur Dioxide ($\text{SO}_2$): This is a pungent, irritating gas produced by burning sulfur or sulfur-containing materials. It is a significant air pollutant and is not used as Laughing Gas.

Therefore, based on the common name and chemical properties, Nitrous Oxide is correctly identified as Laughing Gas.