Is Water (H2O) ionic or covalent? Types of bond in H2O
Water is one of the important fluids for all living things on earth. It is tasteless, colorless, and odorless having the chemical formula H2O. At standard temperature and pressure, the liquid state of H2O is known as water. Almost 70% of the earth is covered by water in the form of oceans and seas. Water also exists in form of ice and steam vapor.
In this article, we will discuss Is (water) H2O ionic or covalent? bond types in H2O and all explanations regarding the nature of bonds present in the water molecules.
Is H2O ionic or covalent?
Water (H2O), like hydrogen fluoride, is a covalent molecule. It’s both atoms (hydrogen and oxygen) are nonmetal, which is linked together by a covalent bond. The difference of electronegativity between oxygen (O) and hydrogen (H) atoms on the Pauling scale is not big enough to make an ionic bond in the H2O compound.
Name of Molecule
Water
Chemical formula
H2O
Molar mass
18.01528 g/mol
Bond type
Covalent
Nature
Neutral
pH value
7
Let’s read in detail, why water (H2O) is a covalent compound? How covalent bonds formation takes place in H2O?
A covalent bond is formed when sharing of electrons is done between the atoms to achieve the noble gas configuration and attains stability.
Usually, covalent bonds formed between the two nonmetals, between p-block and p-block, and formed when electronegativity difference between atoms exist less than 2.
Water (H2O) is a covalent compound. Because the bond forms between two hydrogens and one oxygen are covalent in nature.
The covalent bond is formed due to the sharing of an electron that occurs between hydrogen (H) and oxygen (O) atoms in order to complete their octet shell and hence, attains stability.
Every atom wants to attain stability either by sharing electrons or completing the transfer of electrons. Only the nature of the bond is changed as if the sharing of electrons occurs between atoms then the bond is formed called a covalent bond.
Same as when a complete transfer of electrons occurs between the atoms then the bond is formed which is called an ionic bond.
Examples of some compounds that form covalent bonds – H2S, SO2, NH3, NO2, AlCl3, etc.
The covalent bond is formed in H2O because of sharing of electrons occur between hydrogen and oxygen atom.
Let’s see how covalent bond formation takes place in H2O.
First of all, there are two types of atoms present in the water molecules – hydrogen and an oxygen atom.
⇒ The hydrogen atom is a nonmetal that belongs to Group I in the periodic table and has only one valence electron in the outermost shell.
⇒ The oxygen atom is also a nonmetal that belongs to Group 16 in the periodic table and has a 6 valence electron in its outermost shell.
Every atom wants to complete its octet i.e. having 8 electrons in the outermost shell and attaining stability. Atoms can complete their octet by bonding with other elements or atoms with the help of either sharing of electrons or the complete transfer of electrons.
In the case of an H2O molecule, when hydrogen and oxygen atoms are placed together, they will share the electrons with each other to complete their octet and hence, makes a covalent bond.
Note: The hydrogen atom has only one valence electron and for completing the octet it needs one more electron.
Hydrogen atom is an exception to the octet as it needs only two electrons to complete the octet.
Hence, both oxygen and hydrogen will share the electrons with each other and due to this, a bond is formed between them which is called a covalent bond.
As we see in the above figure of covalent bond formation in H2O, hydrogen atoms have one valence electron represented as an orange dot, and oxygen has six valence electrons represented as blue dots in their outermost shell.
The hydrogen atom needs one more electron and the oxygen atom needs two more electrons to complete the octet, hence, both of these will share the valence electrons with each other.
Therefore, the sharing of electrons between hydrogen and oxygen atom makes a covalent bond in H2O or water molecules.
Note: The lone pair electrons can never take parts in chemical bonding or they never share electrons with any of the atoms. The shared pair of electrons is also called bonded pair of electrons.
Why is H2O not a ionic compound?
H2O is not an ionic compound because the bond formed between hydrogen and oxygen is due to sharing of electrons. In ionic compounds, the bond is formed between two atoms by the exchange of electrons from one atom to another.
There is no sharing of electrons involved in ionic compounds. Also, ionic compounds are mostly formed between one metal and another nonmetal. Usually, the electron is completely transferred from the metal atom to the nonmetal in an ionic compound.
In the case of an H2O molecule, the bond formed between hydrogen and oxygen is due to the sharing of electrons. There is no transfer of electrons involved from one atom to another atom in the H2O compound that’s why it forms a covalent bond instead of an ionic bond.
Also, both hydrogen and oxygen are nonmetal and belongs to the p-block in the periodic table, hence, two nonmetal atoms reacting with each other form the covalent bond due to sharing of electrons involved in them.
There are more reasons why H2O forms a covalent bond and not an ionic bond?
⇒ The electronegativity of the oxygen atom is = 3.4
⇒ The electronegativity of the hydrogen atom is = 2.2
∴ The difference in the electronegativity between hydrogen and oxygen atom is = 1.2
According to the Pauling scale of electronegativity-
If the difference of electronegativity between the two atoms exists less than 1.7, then the bond formed between these atoms is covalent in nature.
If the difference of electronegativity between the two atoms exists more than 1.7, then the bond formed between these atoms is ionic in nature.
So, in the case of the H2O molecules, the difference of electronegativity between hydrogen and oxygen atoms is 1.2 which is lesser than1.7, hence, the bond formed between the atoms of the H2O molecule is covalent in nature.
Examples of some ionic compounds – MgO, Na2O, MgCl2, NaCl, etc.
So, Is H2O a pure covalent bond? No, it is not. First of all, understand the actual means of a pure covalent bond.
We know, that H2O is a covalent compound but whether it is pure or not that depends on the sharing of electrons that occur between the atoms(hydrogen and oxygen).
A pure covalent bond is formed when the electronegativity values of the two or more atoms in a molecule are the same. If the electronegativity value is the same for atoms, then the sharing of electrons between them is also equal, hence, the bond forms between them are pure covalent in nature.
In short, a pure covalent bond is formed between the atoms when they share an equal number of electrons.
But H2O or water molecule is not a pure covalent compound because the difference in electronegativity value in hydrogen(2.2) and oxygen(3.4) caused unequal sharing of electrons between them.
The electrons are more shared towards the oxygen atom as it is more electronegative than hydrogen, hence, unequal sharing of electrons occurs in the H2O compound, which makes it a not pure covalent compound.
Is H2O polar covalent or nonpolar covalent compound?
A polar covalent bond is formed when the difference between the electronegativity of atoms, results in between 0.4 to 1.7. Also, in a polar covalent bond, there is unequal sharing of electrons occurs due to the difference in the electronegativity value of atoms.
Due to unequal sharing of electrons, a positive and negative charge is induced on the atoms that generate a dipole moment, and the bond formed between them is called a polar bond.
A nonpolar covalent bond is formed when the difference between the electronegativity of atoms is less than 0.4. Also, in a nonpolar covalent bond, there is equal sharing of electrons occurs due to the very little difference in the electronegativity value of atoms.
There are no charges induced in a nonpolar covalent compound
So, Is H2O a polar covalent or nonpolar covalent compound? Obviously, H2O is a polar covalent compound because the difference in electronegativity between hydrogen and oxygen is 1.2, hence, unequal sharing of electrons occurs between these atoms.
Also, oxygen is more electronegative than hydrogen, hence, it attracts more electrons towards itself. This induces a negative charge on the oxygen atom and a slightly positive charge on the hydrogen atom.
The separation of charges generates the dipole moment directed from positive to negative, hence, due to all these a bond is formed between oxygen and hydrogen, which is called a polar bond.
Tap and distilled water are polar covalent compounds in nature. As unequal sharing of electrons take place between the atoms present in it.
What type of bond is present in H2O (water)?
The covalent bond present in H2O. Because of a significant difference in the electronegativity value between oxygen and hydrogen causes unequal sharing of electrons between them.
What type of bond attracts one water molecule to another?
“Hydrogen bonds form between neighboring hydrogen and oxygen atoms of adjacent water molecules. The attraction between individual water molecules creates a bond known as a hydrogen bond.”
Why is H2O not a pure covalent compound?
Because the difference in electronegativity value in hydrogen(2.2) and oxygen(3.4) caused unequal sharing of electrons between them.
The electrons are more attracted towards the oxygen atom as it is higher electronegative than hydrogen, hence, all these cause uneven distribution of charges on them which makes H2O a not pure covalent compound.
How covalent bond is formed in H2O (water)?
The hydrogen and oxygen atom are nonmetals in nature that have incomplete octet shells. To obtain the octet, both of these want to share the electron with each other.
Hence, the sharing of electrons between hydrogen and oxygen leads to the formation of a covalent bond in the water (H2O) molecule.
Summary
That’s all, we have done almost all concepts and possible explanations about Is water (H2O) ionic or covalent? Bond types in H2O, why H2O is covalent and not an ionic compound? How covalent bond is formed in water (H2O)? Is covalent bond forms in H2O molecule is polar or nonpolar in nature?
Let’s take a quick overview of all the things we have studied in this article.
Is water (H2O) ionic or covalent? H2O (water) is a covalent compound. Because the difference in electronegativity between hydrogen (H) and oxygen (O) causes unequal sharing of electrons that leads to the formation of the covalent bond between them, and forms, H2O a covalent compound.
The covalent bond formed in the H2O molecule is polar in nature.
Water (H2O) is not a pure covalent compound. Because of the unequal sharing of electrons between the atoms.
H2O (water) is not a 100% covalent compound, it has some ionic bond character as well.
The difference in electronegativity between Oxygen (O) and Hydrogen (H) is 3.4–2.2=1.2 which is lower than 1.7, hence, according to the Pauling scale, the bond formed between oxygen (O) and hydrogen (H) atom is covalent, that makes, H2O compound, covalent in nature
Vishal Goyal is the founder of Topblogtenz, a comprehensive resource for students seeking guidance and support in their chemistry studies. He holds a degree in B.Tech (Chemical Engineering) and has four years of experience as a chemistry tutor. The team at Topblogtenz includes experts like experienced researchers, professors, and educators, with the goal of making complex subjects like chemistry accessible and understandable for all. A passion for sharing knowledge and a love for chemistry and science drives the team behind the website. Let's connect through LinkedIn: https://www.linkedin.com/in/vishal-goyal-2926a122b/
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