Properties of hydrogen

In its most common form, hydrogen is a gas. It weighs only about one-fourteenth as much as an equal volume of air. Because it is the light­est gas, it was once used for filling balloons and airships. A volume of 13,080 cubic yards (10,000 cubic meters) of hydrogen at 32° F. (0° C) and 1 atmosphere pressure can lift about 13.5 short tons (12.2 metric tons). However, it is inflammable. So airships are now filled with helium, the next lightest element.

An unusual property of hydrogen is its ef­fect on sound. Because it is lighter than air, sound waves travel more quickly through hy­drogen. The pitch of the sound is thus higher.

As a gas, hydrogen is usually transported in steel cylinders at 120 to 150 atmospheres pres­sure. It is only slightly soluble in water. Al­though it cannot support life, it is also not poi­sonous.

Hydrogen can be condensed to a liquid at a temperature of —464° F. ( — 258° C). In this form it is used as a rocket fuel. It is transported in

thermally insulated containers. Compounds and uses of hydrogen

Hydrogen forms many compounds. It is a com­ponent of water, two atoms of hydrogen com­bining with one atom of oxygen to make a water molecule. It is a part of the common acids and many bases. Hydrogen also forms organic compounds by combining with other chemical elements in plant and animal tissues. It reacts with metals and many other minerals.

About half of the hydrogen produced in­dustrially is converted into ammonia. The am­monia is oxidized (combined with oxygen) to nitrogen oxide, which is then converted to ni­tric acid for making fertilizers and explosives.

Other important uses of hydrogen include the purification of oil refinery products, for ex­ample, the "upgrading" of heavy fuel oil to gas-

Free neutron resulting from fusion reaction

Helium nucleus formed

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A hydrogen bombexplo­sion /right) produces an enormous amount of en­ergy virtually instanta­neously. It works in two main stages. First, an atomic (fission) bomb explodes to produce the extremely high pressure and temperature needed for the second stage, the fusion reaction. In a fission reaction, atoms are split to produce energy. In a fusion reaction (right, top), nuclei of deuterium and tri­tium fuse. This produces a helium nucleus, a free neu­tron, and a large amount of energy. Scientists are trying to develop fusion reactors in which the energy of fu­sion can be controlled and used to generate electricity.

Major groups of elements: Hydrogen 25

oline. Hydrogen is also used in the production of methanol, which is a basic ingredient in many fuels, rubbing compounds, and solvents.

Hydrogen and carbon (coal) together form various hydrocarbons. These are compounds that include petroleum and natural gas, which provide energy for cooking, heating, and run­ning automobiles. A process known as hydro-genation is the adding of hydrogen to liquid fats in order to form solid fats. Hydrogenation of vegetable oils produces margarine. Hydro­genation of animal fats and oils produces semisolid shortenings used in cooking.

Hydrogen is also involved in the production of liquid fuels from coal. This method of pro­ducing energy, however, is uneconomical.

When two hydrogen atoms unite to form a molecule of hydrogen, or when hydrogen unites with oxygen, relatively large amounts of heat are given off. If a method could be found to better control these chemical reactions and store the released energy, hydrogen could be­come the energy carrier of the future.

Scientists have already developed ways of producing hydrogen economically and in quantity from water. They are currently re­searching ways of releasing the energy inside hydrogen more efficiently and safely. Cur­rently, hydrogen fuel powers the main engine of the United States space shuttle while in orbit. A power plant in New York City pro­duces electricity by means of hydrogen fuel. Hydrogen-powered automobiles and commer­cial aircraft are in various stages of develop­ment.

Date: 2015-12-11; view: 1761