Is NaF Ionic Or Covalent: Why, How, Lewis structure, Detailed Explanations


In this article, “is NaF ionic or covalent” , the ionic or covalent properties of NaF with detailed explanations are discussed briefly.

Sodium fluoride is an inorganic species with greater ionic character. It shows all the ionic character like any ionic compounds. This salt is water soluble and white colored.  It has different use like fluoridation of drinking water and pesticides, rat killer and also used to prevent cavities in teeth.

Some questions on sodium fluoride and its chemical behaviour are answered in this article.

Definition of Covalent and Ionic Compound

Covalent and ionic compound are the two most important species of Chemistry. All the molecules or chemical species are basically classified into these two compounds.

Sharing of electrons is the keyword of covalent compound because electronegativity difference between the two atoms is not large. But in ionic compound complete sharing of electrons take place because of the greater electronegativity difference between two consisting atoms.

is naf ionic or covalent
Transferring of Electrons in Ionic Compound.
Image Credit: Wikimedia Commons
Sharing of Electron Cloud in Covalent Compound.
Image Credit: Wikipedia

To know more please check: 10 Ionic Bond Examples: Explanation And Detailed Facts

How is NaF ionic?

NaF is consisted with two atoms one is sodium (Na), an electropositive metal and another one is halogen compound fluorine (F), an electronegative element.  Electronegativity of sodium is 0.93 (in Pauling scale) and for fluorine this value is 3.98 (in Pauling scale). There is a huge electronegativity difference in sodium and fluorine (=3.05).

The large electronegativity difference leads NaF to an ionic compound. The atomic number of sodium is 11 (1s2 2s2 2p6 3s1) and fluorine is 9 (1s2 2s2 2p5). Sodium can easily donate its 3s electron to fluorine and be unipositive sodium metal ion and gain the nearest noble gas electron configuration. Similarly, fluorine can accept the electrons donated by sodium to make the electron configuration like the nearest noble gas.

Sodium Fluoride as an Ionic Compound

Thus, valence electrons of sodium is completely transferred to fluorine which is the main characteristics of any ionic compound.

% of ionic character (% of I.C) of any covalent and ionic compound can be determined using the following formula-

% I.C =16 ( χA – χB) + 3.5 ( χA – χB)2

In this formula χA and χB are the electronegativity of atom A and B respectively.

Using this formula % of ionic character of sodium fluoride is –

  • % I.C = 16 (3.98-0.93) + 3.5 (3.98-0.93)2
  • % I.C = 81.35

This high value of % of ionic character indicates that NaF is an ionic compound.

To know more please follow: 5 Polar Covalent Bond Examples: Detailed Insights And Facts

Why NaF is not a covalent compound?

To be a covalent compound, electronegativity difference between two molecules must be similar or having lesser difference. Thus, electron cloud is shared between two atoms. The electron cloud is shifted more towards that atom having slightly greater electronegativity than the other atom.

In NaF, sodium is completely transferring its electrons to fluorine atom as fluorine is the most electronegative element and sodium is one of the most electropositive elements in periodic table.

From the above evidence it is clear that NaF is an ionic compound. Besides of NaF has a greater amount of lattice energy.

To know more please read: 4 Single Covalent Bond Examples : Detailed Insights And Facts

NaF lewis structure

Lewis structure is invented by Gilbert N. Lewis in 1916 in his article named as “The atom and the molecule”. Lewis structure, also known as electron dot structure, is very much important term to predict the bonded electrons as well as nonbonding electrons.

To determine the lewis structure of any compound the following steps must be maintained-

  • Valance electrons are shown around the respective atoms. Nonbonded electrons are not shown.
  • Atoms must be connected by single bonds. If the total number of electrons in any lewis structure and is ‘n’ and number of single bonds are ‘N’, then (n-2N) number of electrons remain to be placed. These indicate the number of nonbonded electrons.

In this following image the lewis dot structure of water molecule is shown. Oxygen has total 8 electrons with 6 valance electrons. Between these six electrons, two electrons form two sigma bonds with two hydrogen atoms and rest of the fours electrons are shown around the oxygen atom in this picture.

Sodium has its valance electron 1 and fluorine has its valence electron 5. Sodium donates its one valance electron to fluorine and as a result fluorine has 6 valance electrons. So, fluorine has now total 10 and valance electrons 6. These six electrons are shown around the fluorine atom.

To know more please go through: Is Peptide Bond Covalent : How Why, Comparative Analysis and Facts

Frequently Asked Questions (FAQ)

What happens when sodium fluoride reacts with water?

Answer: When sodium fluoride reacts with water, sodium hydroxide (NaOH) and hydrogen fluoride (HF) are formed. NaF + H2O NaOH + HF

Is sodium fluoride soluble in water?

Answer: Sodium fluoride is a polar inorganic compound and water is a polar solvent. Thus, sodium fluoride is soluble in water.

Is NaF a basic salt?

Answer: Yes, sodium fluoride is a basic salt.

Aditi Roy

Hello, I am Aditi Ray, a chemistry SME on this platform. I have completed graduation in Chemistry from the University of Calcutta and post graduation from Techno India University with a specialization in Inorganic Chemistry. I am very happy to be a part of the Lambdageeks family and I would like to explain the subject in a simplistic way. Let's connect through LinkedIn-https://www.linkedin.com/in/aditi-ray-a7a946202

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