G

Gas

PV = nRT; 22.414 L/mol (STP)
Quick Reference
Formula / NotationPV = nRT; 22.414 L/mol (STP)
Also Known AsGas phase, gaseous state, vapour (near condensation point)

What is Gas?

One of the fundamental states of matter characterized by molecules moving freely with weak intermolecular forces. Gases expand to fill their containers, are highly compressible, and have low densities. Their behavior is described by gas laws (Boyle's, Charles's, ideal gas law).

Formula & Notation

PV = nRT; 22.414 L/mol (STP)

Other Names / Synonyms: Gas phase, gaseous state, vapour (near condensation point)

Properties & Characteristics

A gas is a state of matter characterised by widely separated molecules with negligible intermolecular forces, moving rapidly in random directions. Gases have no fixed shape or volume, are highly compressible, and completely fill their container. They are described by the ideal gas law (PV = nRT) and the kinetic molecular theory. Real gases deviate from ideal behaviour at high pressures and low temperatures (van der Waals equation corrects for this).

Uses & Applications

Gases are essential in: industrial processes (O₂ in steelmaking, N₂ as inert atmosphere, Cl₂ in water treatment), energy (natural gas combustion, H₂ fuel cells), analytical chemistry (GC carrier gas: He, N₂, H₂), medicine (O₂ therapy, anaesthetics, NO for pulmonary hypertension), and refrigeration (NH₃, Freon replacements).

Safety Information

Hazardous gas properties: flammable (H₂, CH₄, CO), toxic (Cl₂, H₂S, HCN, CO), asphyxiant (N₂, CO₂, Ar at high concentration), oxidising (O₂, F₂). All gases must be stored in properly secured cylinders away from heat. Gas detectors are essential in enclosed spaces.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Gas
Formula PV = nRT; 22.414 L/mol (STP)
Synonyms Gas phase, gaseous state, vapour (near condensation point)

Frequently Asked Questions

One of the fundamental states of matter characterized by molecules moving freely with weak intermolecular forces. Gases expand to fill their containers, are highly compressible, and have low densities. Their behavior is described by gas laws (Boyle's, Charles's, ideal gas law).

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