Water consists of molecules formed by two hydrogen atoms and one oxygen atom.Oxygen has a higher electronegativity than hydrogen at 2.1 on the Pauling scale with 3.5.
The water molecule has thereby pronounced partial charges, with a negative polarity on the side of the oxygen and a positive on the side of the two hydrogen atoms.
The result is a dipole whose dipole moment in the gas phase is 1.84 Debye.
When water acts as a ligand in a complex bond, water is a monodentate ligand.
Geometrically, the water molecule is angled, with the two hydrogen atoms and the two pairs of electrons directed into the corners of an imaginary tetrahedron.
The angle subtended by the two O-H bonds is 104.45 °.
It deviates from the ideal tetrahedral angle (~ 109.47 °) due to the increased space requirement of the lone pairs of electrons. The bond length of the O-H bonds is 95.84 pm each.
Because water molecules are dipoles, they have pronounced intermolecular attractive forces and can assemble into clusters by hydrogen bonding.
These are not stable, fixed links.
The hydrogen bonding bond is only for a fraction of a second, after which the individual molecules release themselves from the composite and reconnect again with other water molecules in just as short a period of time.
This process is repetitive and ultimately leads to the formation of variable clusters. These processes cause the special properties of the water:
Water has a density of around 1000 kg / m³ (originally the definition of the kilogram), more precisely: 999.975 kg / m³ at 3.98 ° C.
A density anomaly refers to the property based on hydrogen bonding that water has the highest density at this temperature and even increases in volume as it cools down and even increases in volume during freezing, thus losing its density, so that ice floats on water.
the highest specific heat capacity of all liquids at room temperature (75.366 J · mol-1 · K-1 corresponding to 4.18 kJ · kg-1 · K-1 at 20 ° C.),after mercury the greatest surface tension of all liquids; in water it is 72 mN / m at +20 ° C in humid air, so that droplet formation is facilitated,the highest specific enthalpy of enthalpy of all liquids (44.2 kJ / mol corresponding to 2453 kJ / kg at 20 ° C, hence the cooling effect of the transpiration) and the high enthalpy of fusion (6.01 kJ / mol corresponding to 333 kJ / kg; that salt water shows little freezing point depression compared to pure water) a low thermal conductivity (0.6 W / (m K) at 20 ° C).
Depending on the isotopic composition of the water molecule, a distinction is made between normal "light water" (two atoms of hydrogen: H2O), "half-heavy water" (one atom of hydrogen and one atom of deuterium: HDO), "heavy water" of two atoms of deuterium: D2O and "excessive" Water "(two atoms tritium: T2O), with HTO and DTO still other molecules with mixed isotopes occur.
Under high tension, water can form a water bridge between two glass vessels.
[1]Synthesis, electrolysis and chemical use Water as a chemical compound was first synthesized when Henry Cavendish exploded a mixture of hydrogen and air in the 18th century (see Knallgas reaction).
Hydrogen is considered the energy carrier of the future.→ Main article: Hydrogen economyLike electrical energy, hydrogen is not primary energy, but must be produced from primary energy in the same way as electricity generation.
→: Hydrogen production For demonstration purposes, water is broken down into components in the Hofmann water decomposition apparatus. Scheme:2 H 2 O → 2 H 2 + O 2 {\ displaystyle \ mathrm {2 \ H_ {2} O \ rightarrow 2 \ H_ {2} + O_ {2}}} \ mathrm {2 \ H_ {2} O \ rightarrow 2 \ H_ {2} + O_ {2}} proof
Detection Reaction: Water turns white, anhydrous copper sulfate light blue, and blue cobalt (II) chloride paper turns red by water.
In the analysis, water in small quantities (humidity or dryness) is predominantly quantified by Karl Fischer titration (Karl Fischer).
Monographs in pharmacopoeias for the quantitative detection of water are predominantly based on the Karl Fischer titration.Formation of bubbles in boiling water
Heat causes a faster movement of the water molecules. If 100 ° C is reached at the point of heat, it goes there (depending on the germ with more or less bumping) from the liquid to the gaseous state (vapor) whose volume is about 1600 times higher (see water vapor) and which rises as a result of its relative to the surrounding water lower density than more or less large bubbles:
The water begins to boil.
Source: http://p5water.blogspot.com/2018/01/water-molecule.html
The water molecule has thereby pronounced partial charges, with a negative polarity on the side of the oxygen and a positive on the side of the two hydrogen atoms.
The result is a dipole whose dipole moment in the gas phase is 1.84 Debye.
When water acts as a ligand in a complex bond, water is a monodentate ligand.
Geometrically, the water molecule is angled, with the two hydrogen atoms and the two pairs of electrons directed into the corners of an imaginary tetrahedron.
The angle subtended by the two O-H bonds is 104.45 °.
It deviates from the ideal tetrahedral angle (~ 109.47 °) due to the increased space requirement of the lone pairs of electrons. The bond length of the O-H bonds is 95.84 pm each.
Because water molecules are dipoles, they have pronounced intermolecular attractive forces and can assemble into clusters by hydrogen bonding.
These are not stable, fixed links.
The hydrogen bonding bond is only for a fraction of a second, after which the individual molecules release themselves from the composite and reconnect again with other water molecules in just as short a period of time.
This process is repetitive and ultimately leads to the formation of variable clusters. These processes cause the special properties of the water:
Water has a density of around 1000 kg / m³ (originally the definition of the kilogram), more precisely: 999.975 kg / m³ at 3.98 ° C.
A density anomaly refers to the property based on hydrogen bonding that water has the highest density at this temperature and even increases in volume as it cools down and even increases in volume during freezing, thus losing its density, so that ice floats on water.
the highest specific heat capacity of all liquids at room temperature (75.366 J · mol-1 · K-1 corresponding to 4.18 kJ · kg-1 · K-1 at 20 ° C.),after mercury the greatest surface tension of all liquids; in water it is 72 mN / m at +20 ° C in humid air, so that droplet formation is facilitated,the highest specific enthalpy of enthalpy of all liquids (44.2 kJ / mol corresponding to 2453 kJ / kg at 20 ° C, hence the cooling effect of the transpiration) and the high enthalpy of fusion (6.01 kJ / mol corresponding to 333 kJ / kg; that salt water shows little freezing point depression compared to pure water) a low thermal conductivity (0.6 W / (m K) at 20 ° C).
Depending on the isotopic composition of the water molecule, a distinction is made between normal "light water" (two atoms of hydrogen: H2O), "half-heavy water" (one atom of hydrogen and one atom of deuterium: HDO), "heavy water" of two atoms of deuterium: D2O and "excessive" Water "(two atoms tritium: T2O), with HTO and DTO still other molecules with mixed isotopes occur.
Under high tension, water can form a water bridge between two glass vessels.
[1]Synthesis, electrolysis and chemical use Water as a chemical compound was first synthesized when Henry Cavendish exploded a mixture of hydrogen and air in the 18th century (see Knallgas reaction).
Hydrogen is considered the energy carrier of the future.→ Main article: Hydrogen economyLike electrical energy, hydrogen is not primary energy, but must be produced from primary energy in the same way as electricity generation.
→: Hydrogen production For demonstration purposes, water is broken down into components in the Hofmann water decomposition apparatus. Scheme:2 H 2 O → 2 H 2 + O 2 {\ displaystyle \ mathrm {2 \ H_ {2} O \ rightarrow 2 \ H_ {2} + O_ {2}}} \ mathrm {2 \ H_ {2} O \ rightarrow 2 \ H_ {2} + O_ {2}} proof
Detection Reaction: Water turns white, anhydrous copper sulfate light blue, and blue cobalt (II) chloride paper turns red by water.
In the analysis, water in small quantities (humidity or dryness) is predominantly quantified by Karl Fischer titration (Karl Fischer).
Monographs in pharmacopoeias for the quantitative detection of water are predominantly based on the Karl Fischer titration.Formation of bubbles in boiling water
Heat causes a faster movement of the water molecules. If 100 ° C is reached at the point of heat, it goes there (depending on the germ with more or less bumping) from the liquid to the gaseous state (vapor) whose volume is about 1600 times higher (see water vapor) and which rises as a result of its relative to the surrounding water lower density than more or less large bubbles:
The water begins to boil.
Source: http://p5water.blogspot.com/2018/01/water-molecule.html
