86 - nitrous oxide (N2O)

Nitrogen oxide; Dinitrogen monoxide; Dinitrogen oxide; Laughing gas; nitrogen monoxide;

• Industries
Applications

• Pharmaceuticals
Nitrous oxide is used as gas propellant for aerosols packaging.
• Food and Beverage
Nitrous oxide is used as gas propellant for aerosols packaging.
• Laboratories & analysis
Nitrous oxide is a comburant for the flame in atomic absorption spectrophotometry.
N2O is used in calibration gas mixtures for petrochemical industry; environmental emission monitoring, industrial hygiene monitors and trace impurity analyzers.
• Electronics
In semiconductor manufacturing, nitrous oxide can be the oxygen source for chemical vapor deposition (CVD) of silicon oxynitride (doped or undoped) or silicon dioxide.
• Other industries
Combustive for engine of scale models

Gas Properties
Molecular Weight

* Molecular weight : 44.013 g/mol

Solid phase

* Melting point : -91 °C
* Latent heat of fusion (1,013 bar, at triple point) : 148.53 kJ/kg

Liquid phase

* Liquid density (1.013 bar at boiling point) : 1222.8 kg/m3
* Liquid/gas equivalent (1.013 bar and 15 °C (59 °F)) : 662 vol/vol
* Boiling point (1.013 bar) : -88.5 °C
* Latent heat of vaporization (1.013 bar at boiling point) : 376.14 kJ/kg
* Vapor pressure (at 20 °C or 68 °F) : 58.5 bar

Critical point

* Critical temperature : 36.4 °C
* Critical pressure : 72.45 bar

Gaseous phase

* Gas density (1.013 bar at boiling point) : 3.16 kg/m3
* Gas density (1.013 bar and 15 °C (59 °F)) : 1.872 kg/m3
* Compressibility Factor (Z) (1.013 bar and 15 °C (59 °F)) : 0.9939
* Specific gravity (air = 1) (1.013 bar and 21 °C (70 °F)) : 1.53
* Specific volume (1.013 bar and 21 °C (70 °F)) : 0.543 m3/kg
* Heat capacity at constant pressure (Cp) (1.013 bar and 15 °C (59 °F)) : 0.038 kJ/(mol.K)
* Heat capacity at constant volume (Cv) (1.013 bar and 15 °C (59 °F)) : 0.029 kJ/(mol.K)
* Ratio of specific heats (Gamma:Cp/Cv) (1.013 bar and 15 °C (59 °F)) : 1.302256
* Viscosity (1.013 bar and 0 °C (32 °F)) : 0.000136 Poise
* Thermal conductivity (1.013 bar and 0 °C (32 °F)) : 14.57 mW/(m.K)

Miscellaneous

* Solubility in water (1.013 bar and 5 °C (41 °F)) : 1.14 vol/vol

Inhalant effects

Nitrous oxide (N₂O) is a dissociative drug that can cause analgesia, depersonalization, derealization, dizziness, euphoria, sound distortion and slight hallucinations. Brain damage is not listed among the possible harmful effects of nitrous oxide in the NIDA Community Drug Alert Bulletin on Inhalants.^[11]

In medicine

Previously, nitrous oxide was typically administered by dentists through a demand-valve inhaler over the nose that only releases gas when the patient inhales through the nose; full-face masks are not commonly used by dentists, so that the patient's mouth can be worked on while the patient continues to inhale the gas. Current use involves constant supply flowmeters which allow the proportion of nitrous oxide and the combined gas flow rate to be individually adjusted. The masks still obviously cover only the nose.

Because nitrous oxide is minimally metabolized, it retains its potency when exhaled into the room by the patient and can pose an intoxicating and prolonged-exposure hazard to the clinic staff if the room is poorly ventilated. Where nitrous oxide is administered, a continuous-flow fresh-air ventilation system or nitrous-scavenging system is used to prevent waste gas buildup.

Nitrous oxide is a weak general anesthetic, and so is generally not used alone in general anesthesia. In general anesthesia it is used as a carrier gas in a 2:1 ratio with oxygen for more powerful general anesthetic agents such as sevoflurane or desflurane. It has a MAC (minimum alveolar concentration) of 105% and a blood:gas partition coefficient of 0.46. Less than 0.004% is metabolised in humans.