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Write short note about the physical properties of water and relationship between density of water and temperature?

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تاريخ النشر: 2016/10/11
Lubna Amer
من قبل Lubna Amer , محلل كيميائي , شركة الراية الطبية

Properties of water

"Hydrogen monoxide" redirects here. For the hoax involving the chemical name of water, see Dihydrogenmonoxidehoax.

"H2O" and "HOH" redirect here. For other uses, see H2O(disambiguation) and HOH(disambiguation).

Water (H2O) is a polarinorganiccompound that is at roomtemperature a tasteless and odorless liquid, nearly colorless with a hintofblue. The simplest hydrogenchalcogenide, it is by far the most studied chemical compound and is described as the "universal solvent" for its ability to dissolve many substances. This allows it to be the "solvent of life".[] It is the only common substance to exist as a solid, liquid, and gas in nature.

Water molecules form hydrogenbonds with each other and are polar. This polarity allows it to separate ions in salts and strongly bond to other polar substances such as alcohols and acids, thus dissolving them. Its hydrogen bonding causes its many unique properties, such as having a solid form less dense than its liquid form, a relatively high boilingpoint of °C for its molarmass, and a high heatcapacity.

Water is amphoteric, meaning it is both an acid and a base—it produces H+ and OHions by self-ionization. This regulates the concentrations of H+ and OH ions in water.

Because water is a very good solvent, water is rarely pure and some of the properties of impure water can vary from those of the pure substance. However, there are also many compounds that are essentially, if not completely, insoluble in water, such as fats, oils and other nonpolar substances.

 

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Nagy Emara
من قبل Nagy Emara , Process expert - R&D department , KANDIL STEEL GROUP

 

Water have a chemical symbol of H2O and with structure of H-OH , so water molecule is the strangest chemical molecule where it has both acid and alkaline characters, it has(H) proton with positive charge, and (OH) with negative charge. the two opposite charges makes water molecule have dipole structure with partial positive and partial negative charge, the presence of the two oppositely charge makes water have the ability to dissolve both acidic and alkaline compounds without affecting their pH values. The second point is the relation to the density, pure water have density value of 1 gram per 1 cubic millimeter, while impure water density is more than one due to the effect of the mixed contaminants density, so swimming in sea water is easier than in lacks and reveres water, when water heated the internal water molecules spaces increases till the limit of librating some of water molecules out of the solution as vapors, and as temperature increases as the libration increases, as vapor increases also.

 

Daniel Njihia
من قبل Daniel Njihia , Sales Executive/Promoter , Giordano

The density varies with temperature, but not linearly: as the temperature increases, the density rises to a peak at 3.98 °C (39.16 °F) and then decreases; this is unusual. Regular, hexagonal ice is also less dense than liquid water—upon freezing, the density of water decreases by about 9%.

مستخدم محذوف‎
من قبل مستخدم محذوف‎

Water means when you press standard temperature and ambient conditions and when 298.15 Kelvin (25 ° S) and the pressure of 100,000 Pascal (1 bar, 14.5 Bassaa, 0.99 Joe), a colorless tasteless as it is colorless when it is in small quantities, it only takes a blue color when increasing the depth of the layers, and the property in the origin and essence of water, and are caused by the selective absorption in the red area of ​​the visible spectrum and the scattering of white light, [5] the water vapor is essentially colorless gas. [6]

Water molecular structure consists theoretically so that the oxygen atom is located in the center quad molecular geometry surfaces where hydrogen Dhirta located in addition to the couple's cyber (present on the oxygen atom) on the corners of the tetrahedral shape. But common to the molecular structure of water curved and non-linear, as an Association of H-O-H angle amount of 104.45 °. The value of the smallest of the systemic value of 109.47 tetrahedral bond angle, and is due to defend cyber couple to occupy far away as possible from each other by Vesper theory. The length of the O-H bond in the water molecule picometre 95.84. Since Electronegativity oxygen atom by Paulng scale (3.5) higher than the hydrogen atom (2.1), carry oxygen atom a partial negative charge; while the hydrogen atom bearing a partial positive charge, thus the water molecule bi-polar The determination of the pole of $ 1.84 Debye. Water can on the basis of that to form hydrogen bonds between the molecular. These factors lead to the existence of the power of a strong correlation between molecular, which explains the appearance of large water surface tension property, [7] In addition to capillary action. Explain the surface tension of water characteristic phenomenon of the possibility of parking light insect weight on the surface of the water, and the ability to form droplets; while the capillary action, which refers to the tendency of water to climb to the top of a high capillary tube is opposite to the force of gravity, important and vital property when vascular plants such as trees. [8]

Water is good polar solvents, usually referred to as a "solvent in general." Know chemicals soluble (soluble) in water as hydrophilic materials (Hedrofelih), such as salts and sugars, acids, alkalis, and some gases such as oxygen and carbon dioxide. On the other hand, you know the chemicals that are miscible with water (such as fats (oils, grease, etc.) as hydrophobic (hydrophobic). On the other hand, mixes water with many liquids Kalekhullac (eg ethanol) in all proportions, forming a combination has certain qualities, including being azeotrope (mix Oziotroba). but the contrast does not mix water with most of the organic oils, with the recent form with a density lower layer floating on the surface of the water.

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