Heavy water, its preparation and properties

In the past, people did not think of that is water and what is its origin.It was felt that this element, but now we know that it is a chemical compound.

In 1932, the world had spread the news that on the planet Earth have but a simple and heavy water.Now we already know that it can be 135 isotope varieties.

composition

Heavy water, which is also called deuterium oxide, the chemical composition is different from a simple routine, but instead of hydrogen atoms in the water, it contains two heavy isotopes of hydrogen, the so-called deuterium.Heavy water has the formula 2H2O or D2O.Externally there is no difference between heavy and simple liquid but their properties are different.

Chemical reactions in heavy water flows weaker than usual.

Heavy water is slightly toxic.Research experiments have shown that replacement of hydrogen by deuterium atoms lung by 25%, causes infertility in animals.If a further increase of its content in water, the animal dies.However, some organisms survive at 70% deuter

ium (ciliate slipper).A man without health consequences can drink about a cup of the liquid.Thus deuterium excreted within a few days.

Heavy water has the property to accumulate in the electrolyte balance, if carried out reusable water electrolysis.It absorbs couple simple liquid outdoors, ieIt is hygroscopic.

One of the most important properties of this type of water is that it almost does not absorb the neutrons, and this allows it to be used in nuclear reactors for the process of braking neutrons, while it is used as a chemical tracer.

Heavy water, getting

In the years 1933-1946 he was the only method of enrichment electrolysis.Later there were more advanced technologies.Modern mass production in the input stream using a liquid distilled from the electrolyte, with the content in it of heavy water 0.1-0.2%.

first concentration step applies the two-temperature countercurrent hydrosulphuric technology of isotope exchange, the concentration of heavy water at the outlet is 5-10%.The second stage - cascaded electrolysis of alkaline solution at zero temperature, outlet - 99,75-99,995%.

Russian scientists have developed proprietary technology for the production and purification of heavy water.In 1995, the facility, with its high efficiency, was put into commercial operation.Production of fully meet the needs of heavy water, in any amount, and also allows you to export it abroad.

Application

Heavy water is used in a variety of biological and chemical processes.Scientists have determined that such a liquid prevents the development of bacteria, fungi, algae, and if it contains 50% deuterium becomes the antimutagenic properties, promotes the biological mass and acceleration of puberty in humans.

European scientists conducted experiments on mice with cancer.Heavy water is destroyed and the disease and its carriers.It has been found that such water is bad for plants and animals.In the experimental, which watered with heavy water, the kidneys were destroyed and upset metabolism.At high doses the animals died of water.With a small volume (25%), the animals gained weight and bring good issue, and increased egg production in chickens.

The question of what happens if you completely get rid of deuterium, is still open.

comparison of the properties of light and heavy water

answer to the question about the difference between natural light and heavy liquid depends on to whom it was assigned.

chemical properties between them there is almost no difference.In each of these, sodium hydrogen equally allocates the electrolysis and the one and other water equally degraded, their chemical properties is also the same, because they have the same composition.

physical properties of different liquids: boiling point and freezing them different, as they have different density and vapor pressure.Heavy and light water are decomposed by the electrolysis at different speeds.

From a biological point of view - quite a complicated issue, there is still need to work.