Water

Water is a fundamental and essential substance for life on Earth, covering approximately 71% of the planet’s surface. It is a unique compound composed of two hydrogen atoms bonded to one oxygen atom, forming the familiar H2O molecule. This simple yet powerful structure gives water its remarkable properties that are crucial for sustaining life and supporting various ecosystems.

Importance of Water

Water plays a vital role in numerous aspects of life, from supporting biological functions in organisms to shaping landscapes through erosion and deposition processes. It is essential for hydration, nutrient transport, temperature regulation, and waste removal in living organisms. Additionally, water serves as a solvent for many substances, facilitating chemical reactions and metabolic processes necessary for life.

Properties of Water

One of the most remarkable properties of water is its high specific heat capacity, which allows it to absorb and release large amounts of heat without significant temperature changes. This property is crucial for regulating Earth’s climate and maintaining stable temperatures in aquatic environments. Water also exhibits cohesion and adhesion, enabling it to form droplets, capillary action in plants, and surface tension on bodies of water.

Forms of Water

Water exists in various forms across the planet, including liquid, solid (ice), and gas (water vapor). The water cycle describes the continuous movement of water between these forms through processes such as evaporation, condensation, precipitation, and runoff. This cycle plays a critical role in distributing water resources around the globe and sustaining ecosystems.

Human Impact on Water

Human activities have significantly impacted water quality and availability worldwide. Pollution from industrial waste, agricultural runoff, plastic debris, and other sources has contaminated freshwater sources and marine environments, posing risks to human health and ecosystem stability. Over-extraction of groundwater for agriculture and urban development has led to depletion of aquifers and subsidence in some regions.

Sustainable Water Management

To ensure the availability of clean water for current and future generations, sustainable water management practices are essential. This includes conservation efforts to reduce water waste, implementing efficient irrigation techniques in agriculture, investing in wastewater treatment facilities to recycle water resources, and promoting awareness about the importance of preserving water quality.

Conclusion

In conclusion, water is a precious resource that sustains life on Earth in countless ways. Its unique properties and global distribution make it indispensable for ecosystems, human societies, and the planet as a whole. By understanding the significance of water, practicing responsible stewardship, and implementing sustainable management strategies, we can protect this vital resource for generations to come.

1. https://en.wikipedia.org/wiki/Water – Water – This page provides an overview of water, including its chemical and physical properties, aquaphobia, human right to water and sanitation, hydroelectricity, and marine current power.
2. https://en.wikipedia.org/wiki/Water_content – Water content – This page explains the concept of water content or moisture content, which is the quantity of water contained in a material such as soil, rock, ceramics, crops, or wood. It also describes the four standard water contents that are routinely measured and used.
3. https://en.wikipedia.org/wiki/Water_resources – Water resources – This page explains water resources as natural resources of water that are potentially useful for humans, for example as a source of drinking water supply or irrigation water. It also provides a list of related topics such as water resources law, water rights, and virtual water.
4. https://en.wikipedia.org/wiki/Properties_of_water – Properties of water – This page provides information on the properties of water, including its chemical formula, structure, and reactions. It also explains the anomalous properties of water, such as its high surface tension, boiling point, and heat capacity.

Water (Wikipedia)

For other uses, see Water (disambiguation).

"H2O" redirects here. For other uses, see H2O (disambiguation).

Water is an inorganic compound with the chemical formula H₂O. It is a transparent, tasteless, odorless, and nearly colorless chemical substance, and it is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food energy or organic micronutrients. Its chemical formula,H₂O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state ofH₂O at standard temperature and pressure.

Water

Oxygen, O   Hydrogen, H
Names
IUPAC name Water
Systematic IUPAC name Oxidane
Other names Hydrogen oxide Hydrogen hydroxide (HH or HOH) Hydroxylic acid Dihydrogen monoxide (DHMO) (parody name) Dihydrogen oxide Hydric acid Hydrohydroxic acid Hydroxic acid Hydroxoic acid Hydrol μ-Oxidodihydrogen κ1-Hydroxylhydrogen(0) Neutral liquid
Identifiers
CAS Number	7732-18-5 Y
3D model (JSmol)	Interactive image
Beilstein Reference	3587155
ChEBI	CHEBI:15377 Y
ChEMBL	ChEMBL1098659 Y
ChemSpider	937 Y
DrugBank	DB09145
ECHA InfoCard	100.028.902
EC Number	231-791-2
Gmelin Reference	117
KEGG	C00001
PubChem CID	962
RTECS number	ZC0110000
UNII	059QF0KO0R Y
CompTox Dashboard (EPA)	DTXSID6026296
InChI InChI=1S/H2O/h1H2 Y Key: XLYOFNOQVPJJNP-UHFFFAOYSA-N Y
SMILES O
Properties
Chemical formula	H 2O
Molar mass	18.01528(33) g/mol
Appearance	Almost colorless or white crystalline solid, almost colorless liquid, with a hint of blue, colorless gas
Odor	Odorless
Density	Liquid (1 atm, VSMOW): 0.99984283(84) g/mL at 0 °C 0.99997495(84) g/mL at 3.983035(670) °C (temperature of maximum density, often 4 °C) 0.99704702(83) g/mL at 25 °C 0.96188791(96) g/mL at 95 °C Solid: 0.9167 g/mL at 0 °C
Melting point	0.00 °C (32.00 °F; 273.15 K)
Boiling point	99.98 °C (211.96 °F; 373.13 K)
Solubility	Poorly soluble in haloalkanes, aliphatic and aromatic hydrocarbons, ethers. Improved solubility in carboxylates, alcohols, ketones, amines. Miscible with methanol, ethanol, propanol, isopropanol, acetone, glycerol, 1,4-dioxane, tetrahydrofuran, sulfolane, acetaldehyde, dimethylformamide, dimethoxyethane, dimethyl sulfoxide, acetonitrile. Partially miscible with diethyl ether, methyl ethyl ketone, dichloromethane, ethyl acetate, bromine.
Vapor pressure	3.1690 kilopascals or 0.031276 atm at 25 °C
Acidity (pKa)	13.995
Basicity (pKb)	13.995
Conjugate acid	Hydronium H3O+ (pKa = 0)
Conjugate base	Hydroxide OH– (pKb = 0)
Thermal conductivity	0.6065 W/(m·K)
Refractive index (nD)	1.3330 (20 °C)
Viscosity	0.890 mPa·s (0.890 cP)
Structure
Crystal structure	Hexagonal
Point group	C2v
Molecular shape	Bent
Dipole moment	1.8546 D
Thermochemistry
Heat capacity (C)	75.385 ± 0.05 J/(mol·K)
Std molar entropy (S⦵298)	69.95 ± 0.03 J/(mol·K)
Std enthalpy of formation (ΔfH⦵298)	−285.83 ± 0.04 kJ/mol
Gibbs free energy (ΔfG⦵)	−237.24 kJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Drowning Avalanche (as snow) Water intoxication
NFPA 704 (fire diamond)	0 0 0
Flash point	Non-flammable
Safety data sheet (SDS)	SDS
Related compounds
Other cations	Hydrogen sulfide Hydrogen selenide Hydrogen telluride Hydrogen polonide Hydrogen peroxide
Related solvents	Acetone Methanol Hydrogen fluoride Ammonia
Supplementary data page
Water (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Because Earth's environment is relatively close to water's triple point, water exists on Earth as a solid, a liquid, and a gas. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor.

Water covers about 71% of the Earth's surface, with seas and oceans making up most of the water volume (about 96.5%). Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor, clouds (consisting of ice and liquid water suspended in air), and precipitation (0.001%). Water moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea.

Water plays an important role in the world economy. Approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies has been, and continues to be, a major source of food for many parts of the world, providing 6.5% of global protein. Much of the long-distance trade of commodities (such as oil, natural gas, and manufactured products) is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating in industry and homes. Water is an excellent solvent for a wide variety of substances, both mineral and organic; as such, it is widely used in industrial processes and in cooking and washing. Water, ice, and snow are also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, diving, ice skating, snowboarding, and skiing.

Water (Wiktionary)

English

Wikiquote

Wikiversity

Pronunciation

• (United Kingdom)
  • (Received Pronunciation) IPA^(key): /ˈwɔːtə/
  • (England, Estuary English) IPA^(key): [ˈwoːʔɐ], [ˈwoːʔə]
  • (England, Cockney) IPA^(key): [ˈwoʊʔə], [ˈwɔoɾɐ]
  • (Northern English, dated, obsolete elsewhere) IPA^(key): /ˈwætəɹ/, [ˈwatə], [ˈwaɾɚ]
  • (Scotland) IPA^(key): /ˈwɔtər/, [ˈwɔtər]
  • (dialectal) IPA^(key): /ˈwɒtə/, /ˈwɒtəɹ/
• (North America)
  • (General American) IPA^(key): /ˈwɔtəɹ/, [ˈwɔɾɚ], enPR: wôtər
  • (US, cot–caught merger, Canada) IPA^(key): /ˈwɑtəɹ/, [ˈwɑɾɚ], enPR: wŏtər
  • (NYC) IPA^(key): [ˈwɔəɾə]
  • (Philadelphia) IPA^(key): /ˈwʊtəɹ/, [ˈwʊɾɚ]
  • (Western Pennsylvania) IPA^(key): /ˈwɔɹtəɹ/, [ˈwɔɹɾɚ]
• (General Australian, New Zealand) IPA^(key): /ˈwoːtə/, [ˈwoːɾə]
• (Ireland) IPA^(key): /ˈwɔːtəɹ/, [ˈwɒːθ̠ɚ]
• (Indian English) IPA^(key): [ˈwɔʈə(r)], [ˈʋɔʈə(r)]
  • (Tamil English) IPA^(key): [ˈʋaːʈər(ɯ)], [ˈwaːʈər(ɯ)]
• (General South African) IPA^(key): [ˈwoːtə]
• Hyphenation: wa‧ter
• Rhymes: -ɔːtə(ɹ)

Etymology 1

From Middle English water, from Old English wæter (“water”), from Proto-West Germanic *watar, from Proto-Germanic *watōr (“water”), from Proto-Indo-European *wódr̥ (“water”).