NaCl is not a covalent bond. It forms an ionic bond. The ionic compound sodium chloride, also known as salt, has the chemical formula (NaCl), which denotes a 1:1 ratio of sodium cation to chloride anion. It is a white, crystalline substance that is solid. In aqueous form, it is known as a saline solution. The salt that contributes the most to the saltiness of seawater and the extracellular fluid of many multicellular organisms is sodium chloride. Its edible form of table salt is widely used as a flavor and for food preservation. The sodium chloride concentration of seawater ranges from 1% to 5%. NaCl has a molecular weight of 58.44g/mol. The pH of sodium chloride is 7. Let's lean more on "Is NaCl a Covalent Bond?"

1. Covalent and Ionic Compound A covalent compound is created when two nonmetals or two p-block elements combine and share a valence electron to complete the octet and establish stability. When two atoms share valence electrons, a bond is formed that is referred to as a covalent bond. Condition for the formation of a Covalent Bond

• Elements should be nonmetals

• Elements should belong to p-block

• The electronegativity difference between atoms should be less than 1.7. According to the Pauling scale- ➤ The bond formed between the atoms is ionic if the difference in electronegativity between them is

According to the Pauling scale- ➤ The bond formed between the atoms is ionic if the difference in electronegativity between them is more than 1.7. ➤ The bond formed between these atoms is covalent if the difference in electronegativity between them is less than 1.7. Ionic bonding results in the formation of ionic compounds. One atom transfers its electrons to another in a process known as electron transfer to create an ionic bond. An atom of one element loses one or more electrons during an electron transfer, whereas another atom gains those electrons. In an electron transfer, both atoms involved become ions.

2. Why is NaCl an Ionic Compound? The metal and the non-metal combine to create an ionic bond by donating and accepting electrons. In the NaCl molecule, chlorine is a nonmetal that is a member of the halogen family, while sodium is a metal that is a member of the alkali metal group. There are 11 protons and 11 electrons in the sodium atom. In the 3s subshell, there is only one valence electron. There are 17 protons and 17 electrons in the chlorine atom. There are seven valence electrons in the third shell. Being electropositive, the sodium atom loses its single valence electron, which Chlorine will accept. All of this leads to the formation of ions, such as Na⁺ and Cl^-, which are then bonded together by the electrostatic force of attraction to form an ionic bond. Thus, sodium chloride (NaCl) is an ionic molecule in nature due to the complete transfer of electrons (from Na to Cl) and the development of an ionic connection between Na and Cl ions.

2. How does Ionic bond form in NaCl? The compound NaCl consists a cation and an anion. The electrostatic attraction between these two make the compound. Let's see how it works.

2.1 Formation of cation (Na+) The formation of a sodium cation (Na+) involves the loss of an electron from a neutral sodium atom. In the ground state, a neutral sodium atom (atomic number 11) has 11 electrons in its outermost electron shell. As a result, the electrical configuration of sodium metal is (2, 8, 1). To form a sodium cation, one of these electrons is removed from the atom, leaving it with only 10 electrons. The loss of an electron results in a positive charge on the atom, making it a cation. Its electrical configuration will change if one electron is removed (2, 8). With 8 electrons in the outermost shell, it now possesses an electrical configuration that is similar to that of a noble gas.

As a result, sodium metal becomes stable by losing one of its own electrons, forming the positively charged Na+ ion.

2.2 Formation of the anion (Cl–) The formation of a chlorine anion (Cl-) involves the gain of an electron by a neutral chlorine atom. In the ground state, a neutral chlorine atom (atomic number 17) has 17 electrons in its electron shells. As a result, the electrical configuration of chlorine atom is (2, 8, 7).To form a chlorine anion, an additional electron is added to the atom, making it now have 18 electrons and its electrical configuration now becomes as (2, 8, 8). The addition of an electron results in a negative charge on the atom, making it an anion.

2.3 Electrostatic force attraction between ions (Na⁺ and Cl^–) This formation of sodium chloride typically occurs through a chemical reaction. For example, chlorine gas (Cl₂) can react with a metal such as sodium to form sodium chloride (NaCl), in which the chlorine atom gains an electron from the sodium atom to form a chloride anion (Cl-). Sodium + Chlorine → Sodium cation + Chloride anion

Positive and negatively charged particles are attracted to one another by the non-contact force known as an electrostatic attraction. Therefore, the Na⁺ and Cl^– ions will be drawn to one another and joined by the electrostatic force of attraction. This results in forming of an ionic bond, also known as an electrovalent bond, between the Na⁺ and Cl^– ions.

3. Why is NaCl not a Covalent Bond? NaCl is not covalent due to its electronegativity. This can be explained as: Chlorine electronegativity = 3.16 Sodium electronegativity = 0.93. Therefore, the electronegativity gap between the sodium and chlorine atoms is 3.16 - 0.93 = 2.23. According to Pauling scale, for a covalent bond the value of electronegativity should be less than 1.7. The electronegativity of sodium chloride is 2.23 which is a large difference for a compound to be covalent. This indicates that the bond between NaCl is ionic.

4. The energy involved in Ionic bond formation The formation of ionic bonds in NaCl involves three different forms of energy (a) Ionization enthalpy (b) Electron gain enthalpy (c) Lattice energy

4.1 Ionization enthalpy The amount of energy needed to remove a free electron from an isolated gaseous atom's outermost shell and subsequently change it into a gaseous positive ion is known as ionization enthalpy. Ionization enthalpy, in the instance of ionic bond formation in NaCl, is the energy associated with the release of an electron from the sodium metal.

4.2 Electron gain enthalpy  The enthalpy that results from the addition of one electron to a gaseous isolated atom and the subsequent formation of a gaseous negative ion is known as the electron gain enthalpy. Although the electron gain enthalpy can be positive or negative, it is often negative. It should be noted that a chlorine atom has the largest negative electron gain enthalpy.

4.3 Lattice energy The energy released when a gaseous anion and cation combine to form a mole of an ionic bond is known as lattice energy. The stability of an ionic bond increases with the amount of lattice energy released during bond formation. Therefore, in the ionic bond formation in NaCl, some lattice energy is released when a cation (Na⁺) is attracted by an anion (Cl^–).

Key Points

• The bond formed between the NaCl compound is ionic because the electronegativity of NaCl is larger than 1.7.

• With a total of 11 protons and 11 electrons, sodium has an atomic number of 11. Its electronic configuration is 1s² 2s² 2p⁶ 3s¹.

• Chlorine has an atomic number of 17 and consists of 17 protons and 17 electrons. It has an electronic configuration of 1s² 2s² 2p⁶ 3s² 3p⁶.

• The energy generated during the formation of an ionic bond in NaCl is known as lattice energy.

FAQs What type of bond does sodium chloride, or NaCl, comprise? Due to the significant difference in electronegativity between the sodium and chlorine atoms, the molecule NaCl has an ionic bond. According to the Pauling scale, compounds having a value of greater than 1.7 indicates an ionic character. Why is sodium chloride (NaCl) not covalent? Covalent bonds form when two atoms share electrons, but in the case of the compound NaCl, the sodium atom donates the electron entirely to the chlorine atom, therefore there is no sharing between the sodium and chlorine atoms. Therefore, the nature of the NaCl compounds cannot be covalent. Why does chlorine gain an electron and sodium metal lose one to form an ionic bond in NaCl? The electrical configuration of sodium metal is (2, 8, 1), making it easier for sodium to lose the one electron needed to complete an octet and hence gain stability. Since the nonmetal chlorine already has the electronic configuration (2, 8, 7), the addition of another electron transforms it into the electronic configuration (2, 8, 8), completing the octet and bringing stability. Why is the ionic bond in NaCl so strong? The ionic bond in NaCl is strong because the ions are held together by a large, electrostatic force of attraction. The sodium cation (Na+) has a positive charge, and the chlorine anion (Cl-) has a negative charge. These opposite charges attract each other, forming a strong ionic bond. How does the ionic bond in NaCl affect the physical properties of the compound? The ionic bond in NaCl has a number of effects on the physical properties of the compound. For example, NaCl is a crystalline solid at room temperature, with a high melting point (801 °C) and boiling point (1465 °C). It is also a good conductor of electricity when dissolved in water, due to the movement of ions.