Hydrogen is one of the most abundant elements in the universe. The four giant gaseous planets in our solar system- Jupiter, Saturn, Uranus, and Neptune are also mainly formed out of hydrogen. Our scientists and astronomers estimate that about 90% of the atoms in the surroundings are hydrogen atoms. Hydrogen is a substantial component of more compounds than any other element. Water is the most vital compound of hydrogen found on earth. Hydrogen is a prominent part of petroleum, many minerals, oils, alcohols, acids, cellulose, starch, sugar, fats, and other substances.
At average temperatures, hydrogen is uncoloured, fragrance-free, tasteless, and nontoxic gas comprising the diatomic molecule dihydrogen H2. Also, hydrogen is composed of mainly three isotopes. Unlike other elements, these isotopes have contrasting names and chemical symbols: protium, i.e. one–hydrogen, 1H, Deuterium, i.e. two-hydrogen, 2H (OR “ D “) and tritium (3H), i.e. three-hydrogen. In a naturally occurring illustration of hydrogen, there is one atom of Deuterium, i.e. two-hydrogen for every 7000 H atoms and one atom of radioactive tritium for every 1018 H atoms. The chemical characteristic of the different isotopes is the same due to which they have identical electron structures. Still, they are dissimilar in some physical characteristics because of their unique atomic masses. Elemental deuterium and three-hydrogen, i.e., tritium, have lower vapour oppression than ordinary hydrogen. Thus, when liquid hydrogen evaporates, the bulky isotopes are concentrated in the last portion to evaporate. Decomposition reaction of heavy water, D2O, yields heavy water. Many of the tritiums originate from nuclear power reactions.
Formation of Hydrogen
Other than hydrogen’s natural occurrence, it can also be formed synthetically in labs. Most industries that use hydrogen as raw material produce hydrogen through various synthetic ways. Elemental hydrogen is supposed to be prepared from chemical compounds by breaking chemical bonds. The many ordinary methods of preparing hydrogen are as follows:
By Hydrocarbons and Steam
One of them is water. It is the most inexpensive and most generous source of hydrogen. The passing of steam over coke (an alloyed form of elemental carbon) at 1000 °C gives a combined carbon monoxide and hydrogen called water gas.
Water gas is a combustion fuel. It is easy to make additional hydrogen by blending the water gas with steam in a catalyst to convert the CO to CO2. This reaction is called a water gas shift reaction.
It is also easy to prepare a combined mixture of hydrogen and carbon monoxide bypassing the hydrocarbons from natural gas or fuel, i.e., petroleum and steam above a nickel-based catalyst. Propane is an instance of a hydrocarbon reactant.
By Electrolysis
Hydrogen forms when current flows in one direction, i.e. electricity passing through water restraining an electrolyte such as H2SO4—the ions of hydrogen form at the cathode end, and oxygen deposits at the anode end.
The electrolysis, i.e. decomposition reaction of water, makes hydrogen and oxygen. Due to this, there are twice as numerous hydrogen atoms compared to oxygen atoms. This is because both the components of water are diatomic, and there is twice the volume of hydrogen made at the cathode end as there is oxygen form at the anode end.
By Metals reacting with acid
It is the most suitable laboratory method for generating hydrogen. Metals with lower reduction capability reduce the hydrogen ion in dilute acids to generate hydrogen gas and metal salts. For instance, iron in dilute hydrochloric acid generates hydrogen gas and iron(III) chloride. The reaction of iron with an acid generates hydrogen. In this case, iron reacts with hydrochloric acid.
By Ionic Metal Hydrides reacting with water.
It is easy to produce hydrogen from the reaction of hydrides of the active metals, which hold the very powerful basic H− anion, with water. Metal hydrides are costly but appropriate sources of hydrogen, mainly where space and weight are crucial factors. They are majorly used in the inflation of life jackets, life rafts, and military balloons.
By Chemical Reactions
Under ordinary conditions, hydrogen is comparatively inactive chemically, but it passes into many chemical reactions on heating.
Two-thirds of the world’s hydrogen manufacturing is devoted to producing ammonia, which is a fertilizer and utilized in the production of nitric acid. Vast quantities of hydrogen also play a vital role in the process of hydrogenation.
It is always easy to use hydrogen as a non-combustion fuel. The reaction of hydrogen with oxygen is very heat-releasing, releasing 286 kJ of energy per mole of water produced. Hydrogen blaze without blast under controlled circumstances. Because of the high heat of combustion of hydrogen, the oxygen-hydrogen torch can achieve temperatures up to 2800 °C. The hot flame of this torch is utilized in cutting thick sheets of numerous medals. Liquid hydrogen is also a vital rocket fuel.
React with Elements
On heating, hydrogen reacts with the metals of group 1 with calcium, strontium, and barium (and the more active metals in group second). The chemical compounds formed are crystalline, ionic hydrides that restrain the hydride anion, H−, an active, reducing agent, and an active base, which reacts vigorously with water and as well as with other acids to produce hydrogen gas. The reactions of hydrogen with nonmetals usually generate acidic hydrogen compounds with hydrogen in the 1+ oxidation state. The responses become more exothermic and more potent as the electronegativity of the nonmetal increases.
Applications of Hydrogen
For the past decade, hydrogen is now recognized as a potential commodity for reducing our dependencies on fuel. However, it does have lots of traditional uses. For example, it is still used as a raw material for forming various petrochemical products to reduce the sulfur content of fuel in petroleum refineries. It is also used in the agriculture industry to create multiple chemicals or fertilizers like ammonia and derivative products. Also, it is an ingredient in cleaning products, waste treatment, plastics, cold storage treatments and fabrics, dyes.
In this decade, the petroleum refining industry has the highest demand for hydrogen, followed by the agricultural and manufacturing sectors. Other industries like steel and cement use hydrogen as a high-grade heat source. Because of the high use of hydrogen, it is usually produced by processing methane to form grey hydrogen. According to recent stats, Grey hydrogen emits 9 to 20 kg CO2 for every kg of hydrogen.
Hydrogen is also used in transportation, and it is sometimes referred to as hydrogen mobility—it requires fuel cells similar to combustion engines to generate electricity. Hydrogen is also believed to play a vital role in renewable energy. Because it can be reused to form electricity and stored in the form of chemical energy, it can be done by using electrolyzers, where electricity can be produced from a renewable source and converted to hydrogen.
Conclusion
Hydrogen is one of the most abundant elements in the universe, and its chemistry is genuinely different. Thus, it has some chemical reactivity similar to that of the alkali metals; hydrogen has most of the same chemical characteristics of a nonmetal with a comparatively lesser electronegativity. It formed ionic hydrides with highly active metals, covalent chemical compounds in which it has an oxidation state of −1 with lesser electronegative elements, and covalent compounds in which it has an oxidation state + 1 with most of the electronegative nonmetals. It reacts dynamically with oxygen, fluorine, and chlorine, is less active with bromine, and much less readily with iodine. The hydrogen halides are all acidic when dissolved in water. It is also vastly used across various industries to form finished products with so many unique properties. Recently, it has also been seen as an alternative to traditional fuel sources to generate electricity or conveyance.