The hydrogen economy is currently at a critical juncture. The market requires clean and sustainable energy, and for a wide range of applications, fuel cell technologies seem practical and highly alluring. Additionally, fuel cells are versatile, efficient, and clean. Solid oxide fuel cells in particular are particularly promising. This article will be focusing on the 5 important properties of Hydrogen.
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What is hydrogen?
Hydrogen is a colorless gas that is present in water and air. It is a highly flammable gas that is produced by the breakdown of hydrocarbons. It is a flammable gas but not a supporter of fire. Hydrogen is a major constituent of many compounds including alcohols, ethers, and ammonia. In addition to being a major component of these compounds, hydrogen is also a major component of water. Hydrogen is the simplest molecule that contains only one atom. Hydrogen is the most abundant chemical element in the universe. It has an atomic weight of 1.008 amu and an ionization enthalpy of 1312 kJ/mol.
The 5 important properties of Hydrogen
The properties of Hydrogen are an important topic if you are going to search about hydrogen. You can read 35 interesting things about hydrogen. Properties of Hydrogen can be discussed by dividing it into several classes as below:
1. Physical properties of Hydrogen
The physical properties of Hydrogen can be discussed below:
- The phase of hydrogen that exists at STP is gas.
- The melting point of H2 is -259.16 0
- The boiling point of H2 is -252.88 0
- The density of hydrogen at STP is 0.08988 g/L.
- The triple point of hydrogen is 13.8033 K, 7.041 kPa.
- The critical point of hydrogen is 32.938 K, 1.2858 MPa.
- The heat of fusion of H2 = 0.117 kJ/mol.
- The heat of vaporization of H2 = 0.904 kJ/mol.
- The molar heat capacity of H2 = 28.836 J/mol. K
- The hydrogen gas has no flavor, no smell, and no color.
- It is insoluble in water and lighter than air.
2. Chemical properties of Hydrogen
- The electronegativity of H2 = 2.20 on the Pauling scale
- The oxidation states are -1 and +1.
- Its ionization enthalpy is 1312 kJ/ mol
- Its atomic mass is 1.008 amu.
- Its atomic number is 1.
- The nuclear spin of hydrogen is ½
- Chlorine and hydrogen gas together can cause an explosion.
- Hydrogen loses its electron during oxidation, releasing the H+ ion.
3. Combustion properties of Hydrogen
Although hydrogen is a combustible gas, it does not promote combustion.
- Hydrogen is highly flammable.
- Sparks, heat, or sunlight may set off explosive reactions.
- Hydrogen gas reacts explosively with air in concentrations ranging from 4 to 74% and with chlorine at concentrations of 5 to 95%.
- The temperature at which hydrogen will spontaneously ignite in the air is 500 °C.
Hydrogen has many phases as discussed below.
- Liquid hydrogen: Hydrogen must be cooled below its critical point of 33 K in order to exist as a liquid. However, in order to be fully liquid at atmospheric pressure, H2 must be cooled to 20.28 K (-252.87 °C; -423.17 °F).
- Solid hydrogen: The solid state of the element hydrogen is achieved by lowering the temperature below the melting point of hydrogen, which is 14.01 K (-259.14 °C; -434.45 °F). With a density of 0.086 g/cm3, solid hydrogen is one of the lowest-density solids.
- Metallic hydrogen: Metallic hydrogen can exist as a partial liquid rather than a solid at high pressures and temperatures. When hydrogen is in its metallic phase, it behaves on the characteristics of an electrical conductor.
- Slush hydrogen: At the triple point, slush hydrogen is a mixture of liquid hydrogen and solid hydrogen with a higher density and lower temperature than liquid hydrogen.
- Gas hydrogen: Discussed earlier (Click here)
There are three naturally occurring isotopes of hydrogen as denoted 1H, 2H and 3
- The most common hydrogen isotope is 1H having a surplus of greater than 99.98%. The absence of neutrons makes it distinct from all other stable isotopes.
- 2H is known as Deuterium, the other stable hydrogen isotope has a nucleus with one proton and one neutron.
- Tritium, also referred to as 3H, has one proton and two neutrons in its nucleus. It is so radioactive that it may be used to create luminous paint, making products like watches.