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What are Ionic Compounds?
Ionic compounds refer to those compounds that consist of ion. It is a chemical compound that is neutral overall but mostly consists of cautions (this refers to positively charged ions) and anions (these refer to negatively charged ions).
Ionic compounds can be formed by the freezing, precipitation or evaporating of their constituent ions. Ionic Compounds can be defined as the chemical compound formed by opposite charged ions held together by ions bonds or electrostatic forces.
They are formed between a metal and non-metal. Ionic compounds can also occur when two atoms have a significant variation in their electronegativity, which causes one atom to attract electrons more strongly than the other and cause atoms to lose and acquire electrons.
Examples of these ionic compounds include:
Sodium Chloride (NaCl)
In order to achieve a stable octet configuration, the sodium atom loses one electron from its valency shell. Since the number of protons remains constant and the number of electrons decreases by one, the net charge increases to +1, generating a cation. Sodium donates one of its electrons to Chlorine, which then forms an ionic bond with it to produce NaCl. Chlorine has seven electrons in its valency shell, therefore it needs one electron to become stable.
Other examples include:
Sodium bicarbonate (NaHCO3), Sodium carbonate (Na2CO3), Magnesium sulfate (MgSO4), Potassium chloride (KCl), etc.
What are Molecular Compounds?
When atoms with comparable electro-negativity levels share electrons, these compounds form. They are compounds that exist as discrete molecules. Unlike in an ionic compound, atoms in a molecule exchange valence electrons to form bonds between pairs of atoms. In a carbon dioxide molecule, there are two of these bonds, one between a carbon atom and one of the two oxygen atoms.
The formula for molecular compounds is known as the molecular formula. Every molecular formula specifies the number of atoms in each constituent element of a molecule. A molecular compound is something like water. Water has two hydrogen atoms and one oxygen atom, so its molecular formula is H20.
There are numerous types of molecular compounds. The binary molecular compound is one of these. A binary molecular compound is made up of two non-metallic elements. Prefixes are used to indicate the number of atoms present in each element, for example, carbon dioxide (di signifying 2 atoms of oxygen).
Difference Between Ionic and Molecular Compounds
- Non-metal elements combine to form molecular compounds. Ionic compounds are formed by the combination of metal and nonmetal elements.
- Ionic compounds are made up of ionic bonds, which are formed when atoms are electrostatically attracted to each other. Covalent bonds are used to form molecular compounds, in which electrons are shared among the atoms involved in the formation.
- When cations and anions interact, ionic compounds are formed. When neutral atoms interact with one another, they form molecules.
- Because ionic bonds are so strong, their compounds are mostly solids. Because covalent bonds are so weak, most molecular compounds exist in the gaseous phase.
- Ionic compounds have extremely high melting and boiling points, while molecular compounds have low melting and boiling point.
Comparison Between Ionic and Molecular Compounds
| Parameter of Comparison | Ionic Compound | Molecular Compound |
| Constituent element | Metal + Non-metal | Non-metal + Non-metal |
| Means of formation | Atoms are Attracted towards each other electrostatically | Electrons are shared between the atoms involved in the formation. |
| Formation | Formed when cations and anions interact with each other | Formed when neutral atoms interact with each other. |
| State | Mostly solids | Mostly exist in gaseous or liquid state |
| Boiling Point | High melting and boiling point | Low melting and boiling point |
