Lewis Structure of NaCl

Sodium chloride is an ionic compound with a 1:1 ratio of sodium and chloride ions. Its other name is salt. It is found in the oceans and seas and can also be found in the form of rock salt.

NaCl makes up between 1% and 5% of seawater. It is a white crystalline solid. It has a molecular weight of 58.44g/mol.

Table of Contents

• How to draw Lewis Structure of NaCl
• Crystal Structure of NaCl
• Polarity of NaCl
• Frequently Asked Questions- FAQs

How to Draw Lewis Structure of NaCl

When drawing a Lewis dot structure, we are always attempting to achieve an electron count at which all of the atoms involved are stable and (usually) have full octets. We are also attempting to establish a structure with the smallest formal charge possible. The general rule is to first isolate all of the elements involved and their valence electrons, then begin piecing them together in an attempt to reduce the formal charge and bring all elements involved to an octet.

Sodium and chlorine form an ionic bond, which means that one atom donates an electron and the other accepts it. Each atom receives a charge as a result of this.

Chlorine has seven valence electrons, whereas sodium has one. In order for each atom to form an octet, sodium must lose one electron and chlorine must gain one electron. This would result in a negative charge for chlorine and a positive charge for sodium.

Steps to draw Lewis dot structure of NaCl

Step 1: Count the available valence electrons.

In the periodic table, sodium is in the first group and chlorine is in the 17th.

As a result, the valence electron of-

Sodium = 1

Chlorine = 7

∴ Total available valence electrons = 1 + 7 = 8

Step 2: In ionic compounds, the metal atom donates electrons while the nonmetal atom accepts them.

So, in the case of the NaCl compound, sodium (Na) is the metal that will give away the one electron and forms Na⁺ ion, whereas chlorine is the non-metal that will accept the one electron and forms Cl^– ion.

As a result, in the NaCl Lewis structure, the chlorine ion receives 8 electrons represented as dots in its outermost shell, achieving stability by completing the octet.

Since sodium has only one valence electron in its outermost shell, losing it results in the same electron configuration as neon (noble gas).

As a result, both chlorine and sodium ions have noble gas electron configurations with a full valence shell.

The sodium and chloride ions, which have opposite charges, will attract each other and form an ionic bond.

Crystal structure and Unit Cell

NaCl has a cubic crystal system and a face-centered cubic crystalline structure.

NaCl has four cations and four anions in a face-centered cubic unit cell.

Since there are 4 atoms or ions present in each unit cell of a face centred cubic structure, therefore, the number of NaCl units in a unit cell of NaCl is four.

The cubic unit cell of NaCl can be represented as a face-centered cubic array of anions with an interpenetrating fcc cation lattice (or vice-versa). The NaCl unit cell has the same appearance whether we start with cations or anions at the corners. These ions are all 6-coordinate and have a local octahedral geometry.

Polarity of NaCl

Polar and nonpolar usually occur where covalent bonds between the atoms exist. Since the bond formed between the Na⁺ and Cl^– is ionic, NaCl is neither polar nor nonpolar.

NaCl atoms are separated by positive and negative charge, and the electronegativity difference between Na and Cl is large; we cannot say whether NaCl is polar or nonpolar.

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