N2O

Nitrous oxide (N2O) is a colorless, non-flammable gas with a faint sweet odor. It is commonly called nitrous oxide or laughing gas and has applications in medicine, industry, and food preparation.

Chemically, it is a simple oxide of nitrogen. Its boiling point is −88.5°C, so it is a gas at room temperature and is usually stored as a compressed gas in cylinders. It supports combustion and can intensify fires in the presence of fuels.

Industrial production occurs mainly by thermal decomposition of ammonium nitrate, NH4NO3 → N2O + 2 H2O, at high temperature, with purification before distribution. It is also produced as a byproduct in some chemical processes.

Medical use: inhaled nitrous oxide is used as an analgesic and anesthetic, typically mixed with oxygen. It provides rapid, short-term relief of pain and anxiety but carries risks of hypoxia if not properly administered. Dental procedures often use a 50:50 mix with oxygen. Other uses include a food propellant in whipped cream canisters and as an oxidizer in rocket and automotive applications.

Safety and environmental aspects: Nitrous oxide is an asphyxiant at high concentrations and can cause dizziness, euphoria, and fainting. It supports combustion, so it can worsen fires. Environmentally, N2O is a potent greenhouse gas with a global warming potential around 300 times that of CO2 over 100 years and a long atmospheric lifetime (roughly a century). It is released from soil and manure management, industrial processes, and certain combustion sources, contributing to climate change and stratospheric ozone chemistry.

History: Nitrous oxide was identified in the late 18th century and was later recognized for its anesthetic properties in the 19th century.