What Is Heavy Water: Definition, Properties, and Uses

Heavy water definition and properties

Chemical composition

• Molecular formula: D2O, where D is deuterium (heavy hydrogen), explaining what heavy water is
• Molar mass: 20.02 g/mol compared to 18.01 g/mol for regular water, a key aspect of deuterium oxide explained
• Contains about one deuterium atom for every 6,760 ordinary hydrogen atoms in natural water

Physical properties

• Density: 1.107 g/mL, which is 10.6% higher than regular water, a crucial heavy water definition characteristic
• Boiling point: 101.4°C (compared to 100°C for regular water)
• Melting point: 3.82°C (compared to 0°C for regular water)
• Viscosity: 1.45 mPa·s at 20°C (compared to 0.89 mPa·s for regular water)
• Surface tension: 72.8 mN/m at 25°C (same as regular water)

Chemical properties

• Lower dissociation at a given temperature compared to regular water, further explaining what heavy water is
• pH of 7.44 at 25°C (compared to 7 for regular water)
• Forms a homogeneous mixture with regular water

Uses of heavy water (deuterium oxide)

Nuclear industry

• Used as a neutron moderator in nuclear reactors, allowing the use of natural uranium as fuel, a key application of what heavy water is
• Provides a path to turn natural uranium into plutonium, a fissile material used in nuclear weapons

Scientific research

• Used in nuclear magnetic resonance (NMR) spectroscopy as a solvent, demonstrating deuterium oxide explained in practice
• Employed in infrared spectroscopy for protein analysis
• Used as an isotopic tracer in chemical and biochemical processes
• Utilized in neutrino detection, such as at the Sudbury Neutrino Observatory

Other applications

• Used in metabolic rate testing, further illustrating what heavy water is used for
• Employed in neutron capture therapy for certain medical treatments

Production of heavy water (deuterium oxide)

• Produced through the Girdler sulfide process, the most cost-effective method, an important aspect of deuterium oxide explained
• Other methods include distillation, ammonia-hydrogen exchange, and electrolysis
• Produced in countries like Canada, India, Argentina, and Norway

Biological effects of heavy water

• Can be lethal to multicellular organisms at concentrations over 50%, an important consideration in understanding what heavy water is
• Affects biological systems by altering enzymes, hydrogen bonds, and cell division in eukaryotes
• Has a slightly sweet taste to humans

FAQ

What is heavy water?

Heavy water, also known as deuterium oxide, is a form of water where the hydrogen atoms are replaced by deuterium, a heavier isotope of hydrogen. It has the chemical formula D2O and is about 10.6% denser than regular water.

How does heavy water differ from regular water?

Heavy water has different physical properties compared to regular water. It has a higher boiling point (101.4°C), higher melting point (3.82°C), and higher density (1.107 g/mL). It also has a slightly higher pH and lower dissociation rate.

What are the main uses of heavy water?

Heavy water is primarily used as a neutron moderator in nuclear reactors. It's also used in scientific research, including nuclear magnetic resonance spectroscopy, infrared spectroscopy, and as an isotopic tracer. Additionally, it has applications in neutrino detection and metabolic rate testing.

How is heavy water produced?

Heavy water is primarily produced through the Girdler sulfide process, which is the most cost-effective method. Other production methods include distillation, ammonia-hydrogen exchange, and electrolysis. It's produced in countries like Canada, India, Argentina, and Norway.

Is heavy water dangerous to humans?

Heavy water can be lethal to multicellular organisms at concentrations over 50%. It affects biological systems by altering enzymes, hydrogen bonds, and cell division in eukaryotes. However, in small amounts, it's not immediately harmful and has a slightly sweet taste to humans.