Chinese Name: Ultra-pure Hydrogen, Pure Hydrogen, Ultra-pure Hydrogen

Purity: 99.9999%
Package Specification: 44L
Filling Volume: 5 cubic meters
Filling Pressure: 11 MPa
English Name: Hydrogen
Molecular Formula: H?
Molecular Weight: 2.0157

Related Parameters of Ultra-pure Hydrogen

Chinese Name: Ultra-pure Hydrogen, Pure Hydrogen, Ultra-pure Hydrogen
Purity: 99.9999%

Package Specification: 44L
Filling Volume: 5 cubic meters
Filling Pressure: 11 MPa
English Name: Hydrogen
Molecular Formula: H?
Molecular Weight: 2.0157
CAS Registry Number: 1333-74-0

Related Parameters

Quality Indicators 

Physical and Chemical Properties of Ultra-pure Hydrogen

Hydrogen is the least dense gas known in the world, the substance with the smallest relative molecular mass, and the most abundant element in the universe. It is only 1/14 the density of air, meaning that at 0°C and one standard atmosphere, the density of hydrogen is 0.0899 g/L. Therefore, hydrogen can be used as a filling gas for airships and hydrogen balloons (due to its flammability and safety concerns, airships now often use helium). Hydrogen is primarily used as a reducing agent.

Hydrogen is a colorless gas with a density lower than that of air (among all gases, hydrogen has the smallest density. Under standard conditions, the mass of 1 liter of hydrogen is 0.0899 grams, making it much lighter than the same volume of air). Because hydrogen is poorly soluble in water, it can be collected by the water displacement method. Additionally, at a pressure of 101 kPa and a temperature of -252.87°C, hydrogen can turn into a colorless liquid; at -259.1°C, it becomes a snow-like solid. At room temperature, hydrogen is very stable and does not easily undergo chemical reactions with other substances. However, under changed conditions (such as ignition, heating, or the use of catalysts), the situation becomes different. For example, hydrogen adsorbed by metals like palladium or platinum becomes highly reactive (especially when adsorbed by palladium). Palladium has the strongest adsorption capacity for hydrogen. When the volume fraction in air is between 4% and 75%, it can explode upon encountering an ignition source.

Hydrogen is a colorless, odorless gas with a density of 0.09 g/L under standard conditions (the lightest gas) and is poorly soluble in water. At -252°C, it turns into a colorless liquid, and at -259°C, it becomes a snowflake-like solid.

Molecular Formula: H?
Boiling Point: -252.77°C (20.38 K)
Melting Point: -259.2°C
Density: 0.0899 kg/m3
Relative Molecular Weight: 2.0157
Production Methods: Electrolysis of water (2H?O → 2H?↑ + O?↑, decomposition reaction), cracking, coal gasification, etc.
Triple Point: -254.4°C
Liquid Density (equilibrium state, -252.8°C): 70.77 kg/m3
Gas Density (101.325 kPa, 0°C): 0.0899 kg/m3
Specific Volume (101.325 kPa, 21.2°C): 5.987 m3/kg
Gas-Liquid Volume Ratio (15°C, 100 kPa): 974 L/L
Critical Temperature: -234.8°C
Critical Pressure: 1664.8 kPa
Critical Density: 66.8 kg/m3
Heat of Fusion (-254.5°C, equilibrium state): 48.84 kJ/kg
Heat of Vaporization ΔHv (-249.5°C): 305 kJ/kg
Calorific Value: 1.4×10? J/kg (2.82×10? J/mol)
Specific Heat Capacity (101.335 kPa, 25°C, gas): Cp = 7.243 kJ/(kg·K), Cv = 5.178 kJ/(kg·K)
Specific Heat Ratio (101.325 kPa, 25°C, gas): Cp/Cv = 1.40
Vapor Pressure (normal state, 17.703 K): 10.67 kPa; (normal state, 21.621 K): 53.33 kPa; (normal state, 24.249 K): 119.99 kPa
Viscosity (gas, normal state, 101.325 kPa, 0°C): 0.010 mPa·s; (liquid, equilibrium state, -252.8°C): 0.040 mPa·s
Surface Tension (equilibrium state, -252.8°C): 3.72 mN/m
Thermal Conductivity (gas, 101.325 kPa, 0°C): 0.1289 W/(m·K); (liquid, -252.8°C): 1264 W/(m·K)
Refractive Index nv (101.325 kPa, 25°C): 1.0001265
Flammable Limits in Air: 5%–75% (by volume)

Flammability Rating: 4
Toxicity Rating: 0
Explosiveness Rating: 1
Deuterium, under normal temperature and pressure, is a colorless, odorless, non-toxic, flammable gas and is a stable isotope of ordinary hydrogen. It constitutes 0.0139%–0.0157% of the hydrogen in ordinary water. Its chemical properties are identical to those of ordinary hydrogen, but it has a greater mass and slower reaction rates.

Emergency Response in Case of Fire

Quickly evacuate personnel from the leak-affected area to the upwind side and isolate the area, strictly restricting access. Cut off ignition sources. Emergency responders should wear self-contained positive pressure breathing apparatus and fire-resistant protective clothing. If possible, cut off the source of the leak. Ensure proper ventilation to accelerate diffusion. If feasible, direct the leaking gas to an open area using an exhaust fan or burn it off with an appropriate nozzle. Handle leaking containers carefully; repair and inspect them before reuse. Firefighting Methods: Cut off the gas supply. If the gas supply cannot be cut off immediately, do not extinguish the burning gas. Cool containers with water spray, and if possible, move containers from the fire area to an open space. Fire Extinguishing Agents: Water fog, foam, carbon dioxide, dry powder.