Does salt water conduct current? Does distilled water conduct current? Can you justify it? And not all electricians know this
What is a “pH indicator” - have you heard? It shows the concentration of hydrogen IONS in ABSOLUTELY PURE water. A good approximation to absolutely pure water is deionized water, which is not a useful reagent in semiconductor production. Compared to deionized water, simple distilled water is synonymous with a dirty puddle.What is "ion concentration"? And this is the concentration of CHARGE CARRIERS. And since there is a non-zero concentration of charge carriers, this means that there is conductivity. Therefore, even absolutely pure (deionized) water CONDUCTS CURRENT. Yes, it’s very bad (its resistivity is 17 MOhm*cm), but it conducts. 5 years back from Lenchik Zmanovskaya
Imagine 40,000 jars, each filled with 1 liter of distilled water. Add 1 mg of salt to the first jar, 2 mg to the second, 3 mg to the third, and so on, to the forty-thousandth jar of 40 g. Having tasted the water from the first and second jar, everyone will say that it is unsalted. In the same way, everyone will say that in a forty thousandth jar the water is very salty, the salt content in it is even higher than in sea water. What can we say about the hundredth, two hundredth, eight hundredth, two thousandth? From which jar can water be considered salty?
The same is true with the electrical conductivity of water. If 40 mg of NaOH is dissolved in a liter of water, then the concentrations of Na (+) and OH (-) ions will be equal to 10^ (-3) mol/l, and the concentration of H (+) ions will be 10^ (-11) mol/l. Everyone will say about such a solution that it conducts current. Now let's consider ideal, chemically pure water. Due to self-ionization, it contains a certain amount of H (+) and OH (-) ions. Of course they are hydrated to some extent, but that doesn't matter. At 22 degrees Celsius, the concentrations of H (+) and OH (-) ions are equal to 10^ (-7) mol/l, at 100 degrees Celsius the ion concentration is approximately 5 times higher, something around 10^ (-6.3) mol/l. Most people claim that distilled, and even more so chemically clean water does not conduct current. But there are ions in it, and since there are ions, they conduct current. Now, if we take, for example, a chemically pure hydrocarbon, for example, hexane. It does not undergo self-ionization, there are no ions in it, and it certainly does not conduct current, even theoretically. White Rabbit provided conductivity values for distillate, bidistillate, and deionized water. They are very small, but not equal to zero. So, this means that even deionized water, although very poorly, still conducts current. And if, due to the low conductivity, we assume that it practically does not conduct, then at what value of specific conductivity can we assume that the solution conducts current? With 8, 15, 20, or maybe with 70 or 800 µS/cm? If we approach the issue purely formally, then even perfectly chemically pure water conducts current, but from a practical point of view, it does not. Where should we put the border? The situation is the same as when determining the salinity of water in the above example with 40,000 jars of salt solutions. So, as in that song “Think for yourself, decide for yourself whether to have it or not to have it.”
distilled water does not conduct current, since water itself is a dielectric, and its properties are conductive. receives current from impurities. Distilled water has no impurities. And I'm not an electrician, damn.
5 years back from Uncle_NikitaCompletely purified water is a good dielectric and does not conduct current at all. Current carriers in water are ions.
It would be more correct to speak in your case not about distillate, but about deionized water. The distillate still contains conductive impurities in small quantities.
Who knows the formula of water since school days? Of course, that's it. It is likely that from the entire course of chemistry, many who then do not study it in a specialized manner only have the knowledge of what the formula H 2 O means. But now we will try to understand in as much detail and depth as possible what its main properties are and why there is life without it. on planet Earth is impossible.
Water as a substance
The water molecule, as we know, consists of one oxygen atom and two hydrogen atoms. Its formula is written as follows: H 2 O. This substance can have three states: solid - in the form of ice, gaseous - in the form of steam, and liquid - as a substance without color, taste or smell. By the way, this is the only substance on the planet that can exist in all three states simultaneously under natural conditions. For example: at the Earth's poles there is ice, in the oceans there is water, and evaporation under the sun's rays is steam. In this sense, water is anomalous.
Water is also the most abundant substance on our planet. It covers the surface of planet Earth by almost seventy percent - these are oceans, numerous rivers with lakes, and glaciers. Most of the water on the planet is salty. It is not suitable for drinking or drinking agriculture. Fresh water makes up only two and a half percent of the total amount of water on the planet.
Water is a very strong and high-quality solvent. Thanks to this chemical reactions They pass through the water at great speed. This same property affects the metabolism in human body. It is a well-known fact that the adult body is seventy percent water. In a child this percentage is even higher. By old age, this figure drops from seventy to sixty percent. By the way, this feature of water clearly demonstrates that it is the basis of human life. The more water in the body, the healthier, more active and younger it is. That’s why scientists and doctors from all countries tirelessly insist that you need to drink a lot. It is the water in pure form, and not substitutes in the form of tea, coffee or other drinks.
Water shapes the climate on the planet, and this is not an exaggeration. Warm ocean currents heat entire continents. This is due to the fact that water absorbs a lot solar heat, and then gives it away when it starts to cool down. This is how it regulates the temperature on the planet. Many scientists say that the Earth would have cooled down and turned into stone long ago if it were not for the presence of so much water on the green planet.
Properties of water
Water has many very interesting properties.
For example, water is the most mobile substance after air. From the school course, many probably remember such a concept as the water cycle in nature. For example: a stream evaporates under the influence of direct sun rays, turns into water vapor. Further, this vapor is transported somewhere by the wind, collects in clouds, or even in and falls in the mountains in the form of snow, hail or rain. Further, the stream runs down from the mountains again, partially evaporating. And so - in a circle - the cycle is repeated millions of times.
Water also has a very high heat capacity. It is because of this that bodies of water, especially the oceans, cool very slowly during the transition from a warm season or time of day to a cold one. Conversely, as the air temperature rises, the water heats up very slowly. Due to this, as mentioned above, water stabilizes the air temperature throughout our planet.
After mercury, water has the highest surface tension. It is impossible not to notice that a drop accidentally spilled on a flat surface sometimes becomes an impressive speck. This shows the viscosity of water. Another property appears when the temperature drops to four degrees. Once the water cools to this point, it becomes lighter. Therefore, ice always floats on the surface of the water and hardens into a crust, covering rivers and lakes. Thanks to this, fish do not freeze out in reservoirs that freeze in winter.
Water as a conductor of electricity
First, you should learn about what electrical conductivity is (including water). Electrical conductivity is the ability of a substance to conduct electric current. Accordingly, the electrical conductivity of water is the ability of water to conduct current. This ability directly depends on the amount of salts and other impurities in the liquid. For example, the electrical conductivity of distilled water is almost minimized due to the fact that such water is purified from various additives that are so necessary for good electrical conductivity. An excellent conductor of current is sea water, where the concentration of salts is very high. Electrical conductivity also depends on the temperature of the water. The higher the temperature, the greater the electrical conductivity of water. This pattern was revealed through multiple experiments of physicists.
Water conductivity measurement
There is such a term - conductometry. This is the name of one of the methods of electrochemical analysis based on electrical conductivity solutions. This method is used to determine the concentration of salts or acids in solutions, as well as to control the composition of some industrial solutions. Water has amphoteric properties. That is, depending on the conditions, it is capable of exhibiting both acidic and basic properties - acting as both an acid and a base.
The device used for this analysis has a very similar name - conductivity meter. Using a conductometer, the electrical conductivity of electrolytes in the solution being analyzed is measured. Perhaps it is worth explaining one more term - electrolyte. This is a substance that, when dissolved or melted, breaks down into ions, due to which an electric current is subsequently conducted. An ion is an electrically charged particle. Actually, a conductometer, taking as a basis certain units of electrical conductivity of water, determines its specific electrical conductivity. That is, it determines the electrical conductivity of a specific volume of water taken as an initial unit.
Even before the beginning of the seventies of the last century, the unit of measurement “mo” was used to indicate the conductivity of electricity; it was a derivative of another quantity - Ohm, which is the basic unit of resistance. Electrical conductivity is a quantity inversely proportional to resistance. Now it is measured in Siemens. This quantity got its name in honor of the physicist from Germany - Werner von Siemens.
Siemens
Siemens (can be designated either Cm or S) is the reciprocal of Ohm, which is a unit of measurement of electrical conductivity. One cm is equal to the electrical conductivity of any conductor whose resistance is 1 ohm. Siemens is expressed through the formula:
- 1 cm = 1: Ohm = A: B = kg −1 m −2 s³A², where
A - ampere,
V - volt.
Thermal conductivity of water
Pressurized water is used for splitting, breaking and even cutting rocks. This is actively used in the construction of tunnels, underground premises, warehouses, and subways.
Conclusion
It follows from the article that water, in its properties and functions, is the most irreplaceable and amazing substance on Earth. Does the life of a person or any other living creature on Earth depend on water? Absolutely yes. Does this substance contribute to the management scientific activity a person? Yes. Does water have electrical conductivity, thermal conductivity and other beneficial properties? The answer is also “yes”. Another thing is that there is less and less water on Earth, and especially clean water. And our task is to preserve and protect it (and therefore all of us) from extinction.
Scientists have been arguing about why water conducts current for more than two centuries.
Since water molecules have no charge, they do not conduct electricity. Therefore, distilled water is considered a dielectric, that is, it does not conduct current. But if you add even a very small number of ions to water, its electrical conductivity increases sharply and it becomes a full-fledged conductor. Everyone knows that water and electricity are a very dangerous combination.
To understand this, you need to imagine an atom, which consists of protons, neutrons and electrons. The ratio of neutrons and electrons determines the charge of an atom. If the number of protons is greater than electrons, the charge is positive, if vice versa - negative. As atoms strive for a neutral charge, they give up or take away electrons. When an electron moves from a negatively charged atom to an atom with positive charge an electric current is generated.
Distilled water molecules have no charge. However, such water is rare.
All the water that flows from the tap, contained in rivers, lakes and seas, is a mineral solution of one concentration or another. It contains both positively (calcium, magnesium, sodium, iron) and negatively (chlorine, sulfate, carbonate) charged particles, so this water conducts current well, and the higher the concentration of mineral salts, the better.
When a current passes through water, the oxygen atoms barely have to move. This process can be compared to Newton's famous "cradle", a set of suspended balls lined up in a line. If you pick up one of them and hit the line with it, only the end balls will move, while the rest will stand still.
At the beginning of the 19th century, German chemist Theodor Grotthus proposed a theory that explained why water passes current through itself and why electricity can decompose it into hydrogen and oxygen. He believed that water molecules could capture extra protons and transfer them to each other, like a baton in a relay race, due to the formation of new hydrogen and covalent bonds and their rapid disintegration. Until now, no one knew what water molecules involved in the exchange of protons look like, since it is extremely difficult to monitor this process due to its transience and the extremely small scale on which this reaction occurs.
Yale chemists managed to solve this problem by discovering that such reactions slow down and become visible to instruments when two conditions are met - cooling small quantity water molecules to almost absolute zero and using only "heavy" water - molecules consisting of ordinary oxygen and deuterium, a heavy isotope of hydrogen.
By illuminating such molecules with infrared laser beams and observing changes in their spectrum, scientists were able to see how free deuterium ions attach to heavy water and how they “jump” to the molecule next to it.
As these observations have shown, such exchanges take place not between individual water molecules, but between peculiar “collectives” of their molecules, combining four H2O molecules, reports phys.org. This, in general, confirms what scientists previously suspected based on computer calculations, but could not prove in practice.