Water (H2O) Properties (25 Facts You Should Know)

Water (H2O) is a chemical compound that is made up of two hydrogens covalently bound by an oxygen atom. Let us discuss some of the properties of water.

H2O is a polar inorganic chemical compound which is colourless, tasteless and liquid at room temperature. H2O molecules form a hydrogen bond with each other.

H2O is also called a universal solvent. Let us discuss the basic properties of H2O like density, melting point, boiling point, viscosity, and many more properties.

Water IUPAC name

H2O IUPAC name is oxidane or simply water. It is also called dihydrogen oxide.

Water chemical formula

The chemical formula of water is H2O. the atomic symbol for hydrogen is H and for oxygen is O.

Water CAS number

The CAS number of H2O is 7732-18-5.

Water ChemSpider ID

The ChemSpider ID of H2O is 937.

Water chemical classification

The chemical classification of H2O is as follows

  • H2O acts as both acidic and basic hence, it is amphoteric.
  • H2O has a high hydrating tendency due to its dielectric constant. Many ionic salt easily dissolve in water.

Water molar mass

The molar mass of H2O is 18.02 g/mol.

Water colour

H2O is a colourless liquid which is opaque and transparent.

Water viscosity

The viscosity of H2O is 0.997 at 25 OC.

Water molar density

The molar density of H2O is 997 kg/m3.

Water melting point

The melting point of H2O is 0OC. While in the case of Fahrenheit it is 32 OF.

Water boiling point

The boiling point of H2O is 100OC. While in case of Fahrenheit it is 212OF.

Water state at room temperature

H2O exists as liquid at room temperature.

Water ionic/covalent bond

H2O forms a covalent bond between H and O atoms by sharing electrons with each other.

Water electron configurations

The electronic configuration of any molecule tells us the arrangement of electrons present in their atomic shells. Let us see the electronic configuration of H2O.

The electronic configuration of H is 1s1 and Oxygen is 1s2 2s2 2p4.

Water oxidation state

The oxidation state of hydrogen is +1 and oxygen has +2 oxidation state in H2O molecules.

Water acidity/alkaline

H2O acts as both acidic and basic hence it is amphoteric in nature. Its nature decided on what it is reacting with, or extremely pure H2O is neutral in nature.

Is water odorless?

H2O is odorless. It has no specific odour.

Is water paramagnetic?

If the unpaired electrons are present in the valence shell of an atom it means it is weekly attracted by its magnetic field and paramagnetic. Let us see the nature of H2O.

H2O is not paramagnetic as in water molecules, the hydrogen atom has 1 valence electron and oxygen has 6 valence shells so the 2 hydrogen atoms combine with oxygen and donate their 1 electron eachother leaving no unpaired electrons.

Water hydrates

H2O itself is called a hydrate. When any molecule contains an H2O molecule in a chemical reaction then it acts as a hydrate.

Water crystal structure

H2O crystal structure depends upon its tetrahedral geometry. The oxygen atoms form the center of a tetrahedron. In more than 2 H2O molecules all tetrahedrons are joined together and form a hexagon.

Water polarity and conductivity

  • H2O is a polar molecule as it acts as a polar solvent having high electronegativity.
  • H2O is not able to conduct electric charges hence its conductivity is also low with a value of 5.5 to 10.6 S/m.

Water reaction with acid

When H2O reacts with acid (HCl) it will accept the proton it forms a hydronium ion (H3O) and Cl anion.

HCl + H2O  =  H3O+(aq) + Cl(aq)

HCl + CH3COOH   = CH3COO + H3O+

Water reaction with base

When H2O reacts with base it will donate a proton. When amide ion reacts with ion H2O molecules donate a proton to amide ion and form amine molecules.

H2O + NH2–   = OH + NH3

Water reaction with oxide

The oxides of sulphur and phosphorus form covalent bonds and acidic solution with H2O because when oxide reacts with H2O it forms an acid which donates H+ ions to acid.

SO3 (g) + H2O (l) =  H2SO4

Water reaction with metal

H2O reacts with any metal from the hydroxide of that metal and releases H2 gas.

Na + H2O  =   NaOH + H+

K + H2O    =  KOH + H+

Ca + H2O = CaOH +H+


From the above content, it was concluded that H2O is a colourless, odorless liquid inorganic compound. H2O is also called oxidane its chemical formula is H2O. Also discussed many other chemical properties like IUPAC name, melting point, boiling point chemical properties, and many more.

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