Water is one of the most important and necessary substances for a human being. It is needed for drinking, cooking, domestic and industrial use. Without water, there can be no life. All this is known to every schoolchild. But in this post, we will consider different interesting facts about water, about which you may not know.
Water is one of the most common substances in the Universe
There are places on Earth where water is scarce. Some even think that our planet is lucky enough to have a lot of water here, unlike Venus or Mars. But in fact, water is one of the most common substances in the universe. The fact is that water is made up of hydrogen and oxygen, and hydrogen is the most common element in the universe, and oxygen is the third most common. Easily reacting with each other, hydrogen and oxygen from water. So there is a lot of water in space and the solar system.
Planets, planetary satellites, comets and asteroids, especially those that are far enough away from the Sun to prevent water from becoming steam, are very much made up of water.For example, there is a lot of water on Jupiter's satellite in Europe. The whole satellite is covered with a thick layer of ice, and underneath it, as scientists assume, there is an ocean of liquid water about 100 km deep.
A person can live without water for several days
Usually, a man needs about two liters of water a day. But if there is no water, how many people can live? Most often you can find information that a person without water will live from three to five days. Of course, these are approximate dates, much depends on the condition of the person and external conditions. In a hot desert, a person is unlikely to live without water for more than a day, because he will die of heatstroke. But at low temperatures, you can live without water for a long time. There is a documented case (in Frunze in 1947) when a person without water could live for 20 days.
People can die of thirst not only in the desert but also in the open sea if there is no fresh water. Many shipwreck victims have tried to drink salty seawater, but statistics of such cases show that in this case people usually die even faster. The reason is that the concentration of salts in seawater is much higher than in the human body and their accumulation has the most severe health consequences.
Nevertheless, there are animals on the planet that are far more resilient than humans. For example, African protester fish have learned how to endure drought by burying themselves in the ground and hibernating for several months.And champions in quiet survival can survive complete drying out.
Clean water can be poisoned
It sounds paradoxical, but it's a fact. If you drink too much water, you can get poisoned and die. This will happen because the kidneys will not be able to quickly remove too much water, the body will break the water-salt balance and a person can die. For some people, it can be dangerous to have 3 liters or more of water if it is drunk within an hour.
Some cases of water poisoning have become widely known. For example, in 2007, in California, radio station staff decided to hold a competition by playing a game console. According to its terms, the winner was the one who drinks more water. The winner, Jennifer Strange, who drank 6.5 liters of water, soon felt bad and died of water intoxication 5 hours later.
Water can boil and freeze at different temperatures
It is well known that water freezes at 0 °C and boils at 100 degrees. But in fact, these temperatures can be different. First, both the boiling point and the freezing point of the water depending on the pressure. What is this dependence?
The higher the pressure, the higher the boiling point of the water, and the lower the boiling point, the lower the temperature. If you lower the pressure, the water will boil at an ever lower temperature until the boiling point of 611.73 Pa (or 0.006 atmospheres) equals the freezing point of 0.01 °C. At this and lower pressure, liquid water can no longer exist.
What happens if the pressure rises? The boiling point of the water will also increase (for example, in a pressure cooker, food can be cooked more quickly), but only to a certain extent. At a temperature of 374 °C and a pressure of 22 MPa (218 atm), the water will still turn into steam, in fact, the differences between its liquid and gaseous state will disappear.
The freezing point of the water also depends on the pressure, and when the pressure rises, it first drops to -22 °C at a pressure of 2200 atmospheres and then begins to rise again.
But there are other ways to influence when the water boils or freezes. It is known that especially clean water even at normal pressure may not freeze at temperatures below zero and do not boil at temperatures above 100 degrees Celsius. Such extremely clean water can be cooled down to -33 °C by cooling it carefully and then heated up to 200 °C by heating it gently. However, if the water is shaken or contaminated with impurities, it freezes or boils immediately.
Water is an excellent solvent
Many substances dissolve under the influence of water, decomposing into individual atoms or ions. The properties of the solution differ significantly from those of pure water and those of the source material. For example, neither pure salt nor pure water carries an electric current, as opposed to a salt solution in water.
Solids and gases dissolve in water, while the solubility of solids increases with increasing temperature and the solubility of gases decreases. This means that more oxygen will be dissolved in cold water and less salt will be dissolved in cold water. Some substances dissolve in water in very large quantities. For example, as much as 71 kg of thallium hypophosphite can be dissolved in 1 liter of water.
The water is not as soft as it seems
Usually, the water seems soft and harmless, but when something comes across it at high speed, it seems very hard. For example, jumping into the water from a height of 50 m or more is not much safer than jumping onto concrete.
Water has a surface tension
Water molecules are attracted to each other, and those that are on the surface, the other molecules seem to want to draw into the liquid. Thus water tends to reduce its surface, and since the smallest surface y ball, the smallest amount of water takes the form of spherical droplets. However, in the weightlessness and large quantities of water take the form of a ball.
Some substances dissolved in water can change its surface tension. For example, soap and laundry detergents reduce the amount of soap and laundry detergents that make the water molecules less attractive to each other and better absorb other substances, so that the clothes wash up better.