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Heavy Water
Water that has had its hydrogen replaced with deuterium atoms is called heavy water. Due to the fact that heavy water can slow the velocity of neutrons, it is often used as a coolant in nuclear power plants and as a moderator in nuclear reactors. Heavy water can be naturally occurring in very small amounts. However, it is usually artificially created by enriching water with deuterium atoms.
94 Questions
There are two types of heavy water. The first is where the hydrogen atom is replaced by the Deuterium atom, which contains a neutron. (Thus the atom for practical purposes) is twice as heavy. There is another similar form of hydrogen atom which contains two neutrons, and consequently weighs three times as much as the ordinary Hydrogen. Tritium has a half life of just over 12 years. Deuterium is stable.
If either of these hydrogen isotopes is used to make water, the water is heavier than usual. Commonly differentiated as 'Deuterated water' and Tritiated water'
[There is actually a third variety of heavy water in which 18O is used instead of 16O. This variety is 3H2 18O. Used in the production of positrons for medical use.]
What is the normal freezing point of heavy water?
The normal freezing point of heavy water, which is deuterium oxide (D2O), is around 3.8 degrees Celsius (38.8 degrees Fahrenheit). This is slightly higher than the normal freezing point of regular water (H2O) due to the heavier isotope of hydrogen used in heavy water.
What are the symptoms of heavy water poisoning?
Heavy water poisoning can cause symptoms such as confusion, headache, nausea, vomiting, and difficulty breathing. In severe cases, it can lead to seizures, coma, and death. If you suspect heavy water poisoning, seek medical attention immediately.
What is Coefficient of cubical expansion of heavy water?
The coefficient of thermal expansion depends on the temperature and pressure. It a pressure of 1 atmosphere the coefficient of thermal expansion are:at 4 deg C : –0.1321
at 20 deg C : 0.1212
at 50 deg C : 0.4280
at 100 deg C: 0.7454.
Heavy water, also known as deuterium oxide, is used as a neutron moderator in nuclear reactors to slow down neutrons and control the nuclear fission process. It is also used in scientific research, pharmaceuticals, and in some types of nuclear magnetic resonance (NMR) spectroscopy experiments.
The difference is that a hydrogen atom in heavy water, or deuterium oxide, contains an extra neutron in its nucleus compared to a hydrogen atom in regular water. This extra neutron increases the atomic mass of the heavy water molecule compared to regular water.
In nuclear reactor heavy water is used as?
Heavy water (deuterium) functions as a moderator. It slows down fast neutrons released by fission reactions in order to allow the reaction to be sustained. Fast neutrons pass through the reactor before initiating another fission reaction.
What is the purpose of heavy water?
This is a complicated question to answer, but I'll do my best.
Basicaly heavy water is used as a moderator in a nuclear reactor. It is used to slow the neutrons being directed at the fissionable material, by means of the molecules of the moderator physicaly impacting the incoming neutrons and absorbing some of the kenetic energy they posses, thus slowing them down, in the same way that two billiard balls impacting each other would slow down the incoming one (or both if they were both moving). The reason that the neutrons have to be slowed is that most fissionable materials are more likely to absorb thermal neutrons (2.2km/s) than fast neutrons (14,000km/s).
Light water (the name usually used for regular H2O when talking about nuclear reactors), is the most common type of moderator, because it is cheap, very available, and is more effecient at slowing the incoming neutrons, due to the fact that the hydorgen atoms in the water posses only one proton and one electron, and thus are almost exactly the same mass as the incoming neutrons (the hydrogen atom weighs only as much as one electron more than the neutrons, and electrons are very light when compard to protons and neutrons, which are equal in mass). The problem with using light water as a moderator, however, is that the hydrogen atoms may absorb some of the neutrons, thus preventing them from getting through to the fissionable material. Thus, once the percentage of U-235 (the fissionable isotope of uranium) is too low (such as in natural uranium, where the percentage of U-235 is about 0.72%), then the amount of neutrons getting through the moderator without being abosorbed is not high enough to maintain criticality (the point at which the amount of neutrons being produced is equal to the amount escaping the system or being absorbed but not resulting in fission), and the chain reaction can no longer continue, and the reactor can no longer produce power.
Heavy water, however, is deuterium oxide. Deuterium is an isotope of hydrogen with one proton and one neutron. Thus the hydrogen atom already has one extra neutron, and is much less likely to absorb another. This means that when heavy water is used as a moderator, enough neutrons get through that even with very low levels of U-235 (even the very low levels found in natural uranium), criticality can be maintained, and power is produced. So even though the efficiency of the D2O (heavy water) molecules at slowing the neutrons is slightly less than that of regualr H2O (water, or light water) molecules, the use of heavy water as a moderator allows natural uranium to be used as a fuel with little, if any, enrichment (which is a costly process, and controversial, as enriched uranium can be used to make nuclear weapons).
This is why CANDU (Canadian Deuterium-Uranium) reactors can use natural uranium, or even the waste uranium from conventional light water reactors as fuel.
Why Solubility of salt is less in heavy water than normal?
The solubility of salt is lower in heavy water (D2O) because deuterium atoms in heavy water are heavier than regular hydrogen atoms in H2O, leading to weaker hydrogen bonding forces between the water molecules and salt ions. This weaker interaction affects the ability of heavy water to dissolve and separate the salt ions.
Why is heavy water heavier than regular water?
Because heavy water is D2O and not H2O; the hydrogen atomic nucleus has only one proton, the deuterium has one proton and one neutron. Consequently the properties of the two isotopes are very different. The deuterated water is more dense than the normal water (1,1056 g/cm3 for D2O and 0,9982 g/cm3 for H2O.
What is the boiling point of heavy water?
The boiling point of heavy water is 101.4 °C, or 214.56 °F (374.55 K). More on heavy water can be found by using the link (provided) to the Wikipedia article.
Why is the boiling point of heavy water higher than that of ordinary water?
The boiling point of heavy water is higher than "regular" water because the water is a bit more massive (owing to the extra neutrons stuck to protons in hydrogen nuclei) and more energy is needed to allow the heavy water to change state. Boiling means the molecules gain kinetic energy and "escape" the bonds that are holding the water molecules together in their liquid state. Those same bonds act on the heavy water molecules just like "light" water, but because those molecules are a bit more massive, heavy water molecules need more kinetic energy to "break loose" and "escape" the liquid. That means higher temperatures are required for higher concentrations of heavy water to bring it to a boil. A link is provided to the Wikipedia article on heavy water.
Normal water is made of H2O. That is: two hydrogen atoms and one oxygen atom. Heavy water is made of 2H2O (also known as D2O). That is: one deuterium atom and one oxygen atom. Deuterium is a variation of hydrogen which has a neutron in its nucleus (normal hydrogen has no neutrons).
Do not confuse heavy water with H2O2, which is simply hydrogen peroxide.
The water leak could be caused by a damaged or clogged HVAC drain tube, resulting in water accumulating in the floorboard. Check the drain tube for blockages and clean if needed. It's also possible that the weather seals around the doors or windows may need to be checked for leaks.
What is the chemical structure of heavy water?
Deuterium water (also known as heavy water) has the formula D2O. Xox, Smartiiz. == Heavy water is chemically the same as "regular" water except for its weight. There are two "flavors" of heavy water, and it's due to the nature of the isotope of hydrogen present in the water molecule. Let's look at hydrogen. Hydrogen, the most abundant element in the universe, is almost all composed of a proton and an electron (in the neutral atom). But some hydrogen nuclei have a neutron bound to the proton. There is even a very rare hydrogen nucleus with two neutrons bound to the proton. Now to the water part. Water with an atom of "one-neutron" hydrogen is called deuterium. Water with an atom of "two-neutron" hydrogen is called tritium. These water molecules will be ever so slightly heavier than a "regular" water molecule which has both the hydrogen atoms having a single nucleon. (A nucleon is a particle that makes up the nucleus of an atom; it's a proton or a neutron. See how we sneaked another term in there for you to learn, hmm?) To make things worse as regards the "weight" thing, oxygen, which has 8 protons and almost always has 8 neutrons with it, sometimes has 8 protons and 9 neutrons or 8 protons and 10 neutrons. This makes the "weighing" thing a bit complex, but it isn't unmanagable. In all cases, water is water. But we sometimes take the H2O that is "regular" water and write it as D2O or T2O to designate deuterium or tritium respectively when we're doing nuclear chemistry. And welcome to that world, by the way. Make yourself at home. Links are provided to our friends at Wikipedia.
When did Nazi Germany start its heavy water experiments?
Nazi Germany began its 'heavy water' experiments (or, more precisely, production) in mid-1940 after its invasion and conquest of Norway, which was at the time the world's only source of this key ingredient for the production of a nuclear weapon. Production at this facility ceased several years later as a result of several Allied bombing raids and the subsequent attempted transfer to Germany of the heavy-water supply, which was lost in yet another Allied-inspired sabotage operation.
Heavy water occurs naturally in all water in a proportion of about one part in twenty million. In order to get a certain amount of heavcy water you have to isolate the heavy molecules out of a large quantity of water. The Germans used fresh water because there would have been no point in having to desalinize before they could even begin isolating the heavy water from the regular water. Heavy water is heavy because one of the hydrogen atoms in the water molecule has a neutron in its nucleus along with the proton.
No. No one was seriously trying to make an atom bomb at that time and France was not that important a player in the nuclear research that had already been done. Most of the important nuclear scientists were already in the United States. Michael Montagne
NO. There were several reasons:
1. France had no Atomic Bomb research at that time, and the amount of any "Heavy Water" they may or may not have had was unimportant to England or the United States at tha time. Its importance was not recognized.
2. France probably did have industrial diamonds, as did most industrial nations. BUT to be honest the Germans offered France a pretty good deal when compared to the other occupied nations. France was not totally occupied by the Germans. Southern France remained under the control of Frenchmen (granted they were cooperating with the Nazi's but no other defeated nation got such a deal. (Think about it, the French still controlled their own navy, and colonies.) As a result the French made very little effort to defy the Germans in the early days. This included, among other things -- Industrial diamonds.
Hope this helps, John
Yes, see the following: physics.ubc.cal
absolutely, early in 1940, the french armaments ministry (with british support) negotiated with Norsk Hydro in Norway to obtain their supply of heavy water 185kg. Withfrance facing defeat, the water was moved to the college de France, then on to bordaux. In sept 1940, the heavy water, specialized machine tools, $10m in industrial diamonds and 50 french scientists (all rounded up by the earl of suffolk,who was the liaison in France for the british department for scientific and industrial research), were all loaded on the Denholm Lines ship MS Broompark, under the command of Capt. Olaf Paulsen, who was the only ship's captain will to transverse the girod estuary which had been mined by the Germans. The heavy water was placed in wooden crates and lashed to wooden pallets (which would float free if the broompark was sunk). The broompark arrived safely back in Scotland, with its cargo intact and eventually the heavy water was relocated to the university of Chicago. For his actions in saving the heavy water, capt. olaf paulsen was awarded the "Order of the British Empire email me for a more detailed account as well as a photo of the broompark sailing down the girod estuary (you can see the wooden crates on deck that held the heavy water), capt. paulsen was my grandfather, and my mother has the medals he was awarded in ww2.
Captain Paulsen's OBE was for 'saving his ship when it was torpedoed, see the Fourth Supplement to The London Gazette of Friday the 31st January 1941. Available online - do a search for Paulsen. He deserved a decoration for his work at Bordeaux but did not receive it. The ship delivered the goods and the people to Falmouth on 21 June.
Please contact me through this site for further information - EbbandFlow
Six ships sailed from Bordeaux during 17 - 21 June and 12 from Le Verdon at the entrance to the Gironde. Captain Paulsen's OBE was for taking the Broompark through the minefield. Three months later the Broompark was torpedoed and Capt. Paulsen was awarded Lloyds War Medal for Bravery at Sea for saving his ship and all but one crew member.
Would very much like to see Captain Paulsen's record of his trip.
Hey, I'm Bruno Comer, a researcher in Belgium. I've a complete report on the events with the Broompark in June 17-21 1940. The author is Paul Timbal, a banker from the Antwerp Diamond Bank who kept the diamonds that were saved by the Broompark. The report was recently discovered by me when I wrote a company history of the Antwerp Diamond Bank that celebrated its 75th birthday in 2009. The report will be published by the Royal Historical Commission of Belgium. I'd be very pleased to get to know the grandson of capt. Paulsen and I've some interesting information to offer. Of course, all information that will interest the readers of Paul Timbal's report is welcome too. My coordinates are: Bruno Comer Weststraat 35 8340 Damme Belgium (Bruno.comer@telenet.be) tel 00 32 50 50 00 86.
Why was water pereferred to land when transporting heavy cargo?
Water transportation is often preferred for transporting heavy cargo because water can support greater weights compared to land. Ships and barges have large carrying capacities and can transport massive amounts of cargo in a single trip. Additionally, water routes are typically less congested than land routes, allowing for smoother and more efficient movement of heavy goods.
How does a heavy water nuclear reactor work?
Uranium and Plutonium atoms require nuetrons moving at a certain speed, with a certain amount of kenetic force, to fission properly and often, and to achieve this speed, a neutron moderator is placed between the neutron source and the fuel, which slows the neutrons down by causing them to hit its molecules. Water is often used, since the energy transfer is much more efficient, as hydrogen atoms are almost identical in size to neutrons, possesing only one proton (like two billiard balls striking each other), but hydrogen atoms sometimes absorb neutrons, meaning less get through to cause fissions, and once the concentration of fissionable material drops blow a certain percentage (usualy somewhere around 5%) fission is no longer maintainable. Heavy water posses hydrogen atoms with one extra neutron, so althought the energy transfer is slightly less efficient than with hydrogen atoms, there is much less chance of the atoms abosorbing neutrons, and so many more neutrons get through, allowing the reactor to run on fuel with much lower concetrations of fisionable material (even as low as 0.7%, the natural level of U-235 in Uranium ore). Thus somereacotrs using heavy warer as a neutron moderator (such as the CANDU) can even run on the waste from other, "light water moderated" reactors (light water is just another name for normal water, as opposed to heavy water).
Why do American nuclear plants use light water instead of heavy water in the reactors?
Mainly I believe because the light water PWR was developed for submarines and as compact a reactor as possible was required. Since then of course it (and BWR's) have been up-sized very successfully. Enriched fuel can now be made much more easily and cheaply by centrifuges than by the diffusion method, so to obtain low enriched fuel is more economical. There is also MOX available, though I don't think the US uses this.
See the discussion page as well
Does microwaved water taste different?
If for any other reason the only way a microwave could possibly change the taste of water is to dehydrate the unpurified water's components from the other elements and or foreign particles and or impurities already suspended in the solution. Boiling the water will make this mixture more concentrated thus possibly giving it a slightly different taste. However, I seriously would like to see a study that actually identifies if an electrically heated, microwave heated or kettle heated water would make such a difference to the taste that a human palate could actually differentiate the parameters and decipher as being off-tasting. (Of all the things I would seriously like to see... This one is maybe not too high on the list...)
Heated water is just that, and not much more.
Good luck!
PS: If you are using the heated water to make tea, just don't steep you tea in the mug in the microwave. Also, as you put your tea in the mug, don't look down into a mug right out of the microwave in the way off-chance the water is super-heated. Also, try a little brown sugar and cream with heaver teas. Delectable!
http://www.youtube.com/watch?feature=player_embedded&v=1_OXM4mr_i0
Can you cook with heavy water?
Heavy water (water formed from deuterium and oxygen, not hydrogen and oxygen) does not have different taste. However its higher viscosity may give it a different "feel" in the mouth making it less palatable.
How is it possible to lift heavy mass in water with ease?
There are at least two forces acting on any object in a gravitational field that is immersed in a fluid (Remember that gasses are fluids also; not only liquids.): 1) The force of gravity acting on an object (the object's weight) that is on or near the Earth's surface is constant for all practical purposes regardless of whether the object is immersed in a fluid or not. This is because the object's mass is the same in either case. The weight of the object would only change if its mass changes somehow, for example if the object corrodes in the fluid, if the object or part of it is soluble in the fluid, or if parts of the object are lost either spontaneously or during transfer. 2) The second force acting on an immersed object is a buoyancy force. 3) Additional forces may act on the object if someone or something pushes down or pulls up on the object or exerts a force against one side of it.
Recall that force is a vector, meaning that it has a magnitude and a direction. The gravi-tational force vector points from the center of mass of the object towards the center of the Earth. It is critical that we know the direction of and what causes the buoyancy force so that it may be calculated. As I'm sure you know from experience, the deeper under water something is the higher the pressure on that object. The same is true for a "pool" of air or any gas or mixture of gasses; the air pressure is greater at ground level and diminishes with altitude. When in a gravitational field, the liquid and gas pressures are due to gravity, which means that the denser the fluid, the greater the pressure at any given depth compared to a less dense fluid. (Gravity is responsible for a fluid's pressure in an open system. I want to clarify that we're not considering the case where a gas is compressed in a tank.)
When any object is immersed in a fluid, the pressures on the surfaces of the object vary with depth; the pressure is greater on a surface that is deeper and less on a surface that is shallower. Therefore, there is a pressure difference between the top and bottom surfaces of the submerged object that results in what is called a buoyancy force. You already know that the buoyancy force vector points upwards since the buoyancy force is what allows items to float. To be rigorous though, the origin of the buoyancy force is the geometric center (not necessarily the center of mass) of the object, and the vector's direction is perpendicular to the surface of the fluid directly over the geometric center of the object. This just means that if something is immersed in a pool of water, the buoyancy force would point from the geometric center of the object and would be perpendicular to the surface of the pool. Thus, the gravity and buoyancy force vectors on an immersed object are parallel but point in opposite directions such that they are counteracting one another. The last sentence is the answer to your question, however I would like to explain a little more.
Now we know what causes the buoyancy force and we know its direction, but how much is it? I will omit the mathematics that prove the magnitude of a buoyancy force. Any college physics textbook will certainly contain a complete mathematical description of it. The magnitude of a buoyancy force is exactly equal to the weight (not mass) of the fluid the submerged object displaces. Why the object's weight and not its mass? Because the buoyancy force on an object depends on the density of the fluid in which that object is immersed and on how much of the object is immersed while mass is an inherit property of an object that is the same regardless of where that object is. Hence, buoyancy has the dimensions of Pounds in the English system and Newtons in the kms system.
Let's look at one example to get an idea of how much difference buoyancy makes when a heavy object is submerged in water: I chose to use 1.00 yd3 of solid, fired, red brick. The density of these bricks is 143 lb./ft3. The densities of several types of brick were found on the public website "www.engineeringtoolbox.com" and the density of the brick chosen from that source was the same as what was given on two other public websites. Bricks are usually packaged in 1.00 yd3 units, one cube per palette, and the weight of the bricks is 143 lb./ft.3 • 27.0 ft.3 = 3,861 lb. since 1.00 yd3 = 3.00 ft. • 3.00 ft. • 3.00 ft. = 27.00 ft3.
Suppose that during the construction of a home addition, one cubic yard of bricks needed to be transferred from the materials staging area to a place nearer to where they were needed, and that the easiest way to move the bricks was to fly them over the pool using a small crane. As the bricks were moving over the pool, the braided steel cable connecting the crane hook to one of the steel bands wrapped around the bricks snapped and the entire lot of bricks fell into the pool, however all the bricks stayed together since all three steel bands wrapped around them remained in tact. The job foreman failed to inspect the carbon steel cable used to pick the bricks or he would have noticed that it was significantly corroded in one spot.
It is clear that the crane had to provide a minimum lifting force of 3,861 lb. to lift the bricks from their staging area. What is the minimum lifting force needed to lift the bricks off the bottom of the pool, which is six feet deep with a water temperature of 70.0 ˚F?
The weight of 1.00 ft3 of water at or near the Earth's surface at 70.0 ˚F is 62.30 lb. according to two, independent public sources. Since we know that the buoyancy force on an object submerged in water equals the weight of water displaced by that object, that the volume of water displaced by the bricks equals the volume of the bricks, and we know the density of water at 70.0 ˚F, we can easily calculate the buoyancy force on the bricks as
the weight of 27.0 ft3 water at 70.0 ˚F = 27.0 ft.3 • 62.30 lb./ft.3 = 1,682 lb. The force on the submerged bricks due to gravity is still 3,861 lb., so we simply subtract the buoyancy force from that since the forces are in exactly opposite directions. Remember to always subtract the buoyancy force from the gravitational force. Now we know that the minimum force needed to lift the bricks off the bottom of the pool is 3,861 lb. - 1,682 lb. = 2,179 lb.
This is the force needed to lift the bricks infinitely slowly just until any part of the cube of bricks breaks the water's surface. The moment any part of the bricks is no longer under water, there is no longer any buoyancy force on that part of the cube of bricks.
For fun and practice, calculate the buoyancy force on a helium weather balloon on the Earth's surface at sea level. The empty balloon and the equipment on it weighs 125 lb. Assume that the shape of the balloon is a perfect sphere with a radius of 5.00 ft.
I'll tell you that no balloon can rise forever. What causes the helium balloon described above to only rise to a certain altitude?
What do you use heavy water for?
- Moderator in some types (e.g. Candu) of nuclear reactor to slow high energy fission neutrons to thermal energies.
- In small quantities it can be used for MRI contrast.
- It can be used to slow chemical reactions in water solution.
- etc.
