# What is the critical temperature of helium?

What is the critical temperature of helium? Data Properties of liquid helium Helium-4 Critical temperature 5.2 K (−267.95 °C) Boiling point at one atmosphere 4.2 K (−268.95 °C) Minimum melting pressure 25 bar (360 psi)

## What is the critical temperature of helium?

Data

Properties of liquid helium Helium-4
Critical temperature 5.2 K (−267.95 °C)
Boiling point at one atmosphere 4.2 K (−268.95 °C)
Minimum melting pressure 25 bar (360 psi)
Superfluid transition temperature at saturated vapor pressure 2.17 K (−270.98 °C)

What is the critical pressure of N-hexane?

3.031 MPa
HEXANE

Molecular weight:86.178 Critical temperature: 507.44 K
Melting point: 177.83 K Critical pressure: 3.031 MPa
Normal boiling point: 341.88 K Critical density: 232.8 kg/m3

What is the flash point of hexane?

-22°C c.c.
Flash point: -22°C c.c.

### Is hexane heavier than air?

N-hexane is a clear colorless liquids with a petroleum-like odor. Flash points -9°F. Less dense than water and insoluble in water. Vapors heavier than air.

How do you liquify helium?

To create the liquid and superfluid states, you cool down helium gas to a few degrees above absolute zero. This is achieved by compressing the gas, and then expelling it through a small nozzle.

At what pressure does helium liquify?

approximately 25 atmospheres
He remains liquid at zero temperature if the pressure is below 2.5 MPa (approximately 25 atmospheres). The liquid has a phase transition to a superfluid phase, also known as He-II, at the temperature of 2.17 K (at vapor pressure).

#### What is the boiling temperature of hexane?

69 °C
Hexane/Boiling point

What is the vapor pressure of n hexane?

We report 54 vapour pressures of n-hexane over the temperature and pressure range from (315.7 K, 41.1 kPa) to (504.0 K, 2876.8 kPa), which is about 3 K and 150 kPa below the critical point.

At what temperature does hexane ignite?

Hexane

Names
Flash point −26.0 °C (−14.8 °F; 247.2 K)
Autoignition temperature 234.0 °C (453.2 °F; 507.1 K)
Explosive limits 1.2–7.7%
Lethal dose or concentration (LD, LC):

## Is hexane sensitive to light?

Highly flammable. Insoluble in water. HEXANE may be sensitive to light. It may also be sensitive to prolonged exposure to heat.

Why is it hard to liquify helium?

Answer: Helium is the noble gas which is most difficult to liquefy. The single electron shell of the helium is completely filled and that’s why the intramolecular bonding forces is extremely low in the helium molecules.