Table of Contents
Heavy water (deuterium oxide,2H2O, D2O) is a type of water that only contains deuterium (2H or D, also characterized as heavy hydrogen) instead of the common hydrogen-1 isotope (1H or H, also known as protium) that makes up the majority of the hydrogen in ordinary water. When compared to conventional water, the presence of the heavier hydrogen isotope gives the water unusual nuclear properties, and the increase in mass gives it relatively different physical and chemical properties. The nucleus of a deuterium atom has a neutron and a proton, whereas the nucleus of protium (regular hydrogen) atom contains only a proton. A deuterium atom is nearly heavier than a protium atom due to the extra neutron.
A brief outline
Heavy water molecules have two deuterium atoms instead of the two protium atoms seen in conventional “light” water molecules. In fact, heavy water, as defined by the IUPAC Gold Book, can also refer to water with a larger than usual concentration of deuterium rather than protium hydrogen atoms. Ordinary water, on the other hand, has just around 156 deuterium atoms per million hydrogen atoms, implying that only 0.0156 percent of hydrogen atoms are heavy. As a result, heavy water, as described by the Gold Book, comprises hydrogen-deuterium oxide (HDO) and other D2O, H2O, and HDO combinations containing a higher proportion of deuterium than typical.
Heavy water does not contain any radioactive elements. It has a density around 11% higher than water in its pure form but otherwise is physically and chemically equivalent. Nonetheless, since deuterium is unique amongst heavy stable isotopes in being twice as large as the lightest isotope, the different differences in deuterium-containing water are bigger than in any other widely occurring isotope-substituted substance.
Important concepts
Physical Characteristics
- At STP, heavy water is found to be colourless.
- It occurs as an odourless liquid at normal temperature.
- An ice cube produced of deuterium oxide would sink in regular water because its density is approximately 11% higher than that of H2O.
- When heavy water is contaminated with regular water, it creates a homogenous mixture.
Physical properties
- Water and heavy water have different physical properties in numerous ways. At the same temperature, heavy water is less dissociated than light water, and the true concentration of D+ ions is lower than the true concentration of H+ ions in a light water sample.
- At various temperatures, a genuine acidic pD can be determined from the directly pH meter measured pHa, as follows: pD+ = pHa (apparent reading from pH meter) + 0.41.
- Heavy water is 10.6% denser than ordinary water, and the physical differences between the two can be noticed without the use of special equipment if a frozen sample is thrown into ordinary water and sinks.
- The greater melting temperature of heavy ice can also be observed when the water is ice-cold: it melts at 3.7 °C and consequently does not melt in regular ice-cold water.
- Heavy water lacks the characteristic blue colour of light water because the molecular vibration harmonics that generate weak absorption in the red region of the visible spectrum in light water are moved into the infrared, causing heavy water to take no red light.
Chemical characteristics
- On account of their varying nuclear loads, hydrogen isotopes have changed synthetic properties.
- Changes in the dissolvable properties of water brought about by exorbitant degrees of deuterium can adversely affect natural frameworks.
- When contrasted with weighty water, ordinary water separates positively.
- The grouping of D+ particles in a D2O test is regularly lower than the convergence of H+ particles in an H2O test at a given temperature.
Chemical properties
- Electrolysis: Deuterium can be generated at the cathode when heavy water gets electrolyzed.
- The reaction between alkali and alkaline metal creates di-deuterium, although it takes a long time.
- The action of metallic oxides: Deuter Oxides are produced by a gradual reaction of metallic oxides.
- The action of non-metallic oxides results in the formation of deutero acids. Phosphorus pentoxide and sulphur trioxide are nonmetals oxides that dissolve rapidly in heavy water.
- When heavy water reacts with metallic nitrides, phosphides, and arsenides, deuteron ammonia, deuteron phosphine, and deuteroarsine are produced, respectively.
- Heavy water of crystallization is known to react with a variety of chemicals, resulting in the formation of deuterates. Deuterates are the heavy hydrates that result from this process.
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Also read: Physical Properties of Water
Frequently Asked Questions
Q. What are deuterium oxide’s physical properties?
Ans: The following are the physical characteristics of heavy water:
- It makes a homogenous mixture when mixed with ordinary water.
- At normal temperature, it is an odorless liquid.
- Daydream oxide ice cubes sink in normal water because the density of D2O is 11% higher than that of H2O.
What is fractional distillation, and how will it work?
Fractional distillation is a technique for producing pure deuterium or heavy water. Fractional distillation uses the tiny difference in boiling points of protium oxide (H2O) and deuterium oxide (H2O) to separate heavy water from ordinary water (D2O). This is the most basic method for preparing heavy water using fractional distillation. Normal water seems to have a boiling point of 373K, while heavy water seems to have a boiling point of 374.42K. Electrolysis of alkali-containing water is also used to make heavy water; the procedures are as follows: electrolyte, cathode, and anode.
Is it possible to drink heavy water? Is it perilous?
It is possibly harmful or dangerous if we consume enormous measures of heavy water or, on the other hand assuming heavy water is polished off throughout a drawn-out timeframe. It may result in having the side effects like dizziness and low circulatory strain. Unadulterated heavy water, then again, isn't radioactive and isn't risky to people in limited quantities.