How to draw NaF Lewis Structure? - Science Education and Tutorials

The sodium fluoride chemical formula is NaF. Drawing NaF Lewis Structure is very easy to by using the following method. Here in this post, we described step by step method to construct NaF Lewis Structure. The fluorine and sodium elements come as members of the halogen and alkaline metal family groups from the periodic table respectively. The valence electrons in fluorine and sodium are seven and one respectively. Sodium fluoride is used to make chemical reagents for organic chemical reactions as a brominating agent in organic chemistry.

Table of Contents

Key Points To Consider When Drawing The NaF Electron Dot Structure

A three-step approach for drawing the NaF Lewis structure can be used. The first step is to sketch the Lewis structure of the NaF molecule, to add valence electrons around the fluorine atom; the second step is to add valence electrons to the one sodium atom, and the final step is to combine the step1 and step2 to get the NaF Lewis Structure.

The NaF Lewis structure is a diagram that illustrates the number of valence electrons and bond electron pairs in the NaF molecule. The geometry of the NaF molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory), which states that molecules will choose the NaF geometrical shape in which the electrons have from one another.

Finally, you must add their bond polarities to compute the strength of the one Na+—F- single bonds (dipole moment properties of the NaF molecule). The sodium-fluorine ionic bonds in sodium fluoride(NaF), for example, are polarised toward the more electronegative fluorine in NaF molecule, and because both bonds have the same size and are located around one sodium terminal of the linear structure with three lone pairs (in total eight electrons) on the fluorine atom as fluoride ion(F-), their sum of dipole moment is nonzero due to the NaF molecule’s bond dipole moment and less electron polarity to the sodium atoms and become sodium ion. Because Na+—-F- bonds polarity is not canceled in the NaF molecule due to the presence of four lone pairs of electrons in the linear structure. The sodium fluoride(NaF) molecule is classified as a polar ionic molecular crystal.

The molecule of sodium fluoride(linear-shaped molecular geometry) is tilted, the bond angles between fluorine (as fluoride ion) and sodium (as sodium ion) are 180 degrees. It has a difference in electronegativity values between fluorine and sodium atoms, with central fluorine’s pull being higher than terminal sodium’s in the NaF ionic molecule. But they do not cancel each other due to the linear structure with four lone pairs in the molecular geometry of the NaF molecule.

As a result, it has the nonzero dipole moment. The NaF molecule has a nonzero dipole moment due to an unequal charge distribution of negative and positive charges. But both fluorine and sodium atoms fall on the halogen and alkaline metal family groups in the periodic table respectively. The fluorine atom is a more electronegative value than sodium in the NaF ionic molecule. The NaF molecule has the net dipole moment of non-zero value in the ground state energy level.

NaF molecule has one Na+—–F- single bond. Its dipole moment in the ground state is totally different as compared with the excited state. If it absorbs light may be from visible or UV light. It undergoes pi to pi star and n to pi star transition from ground state energy level to excited state energy level. In the excited state energy level, the NaF ionic molecule shows a definite dipole moment. But it is very dynamic in nature.

Molecules can be classified as polar or nonpolar. The molecule polar behaves in a different manner as compared to nonpolar.

Overview: NaF Lewis Structure

The central atom is fluorine, which is bordered on two terminals with sodium atoms(linear structural geometry), and four lone pairs on the central fluorine atom in the linear molecular geometry. Fluorine has seven outermost valence electrons, indicating that it possesses seven electrons in its outermost shell, whereas sodium also has one valence electron in its outermost shell. To complete the octet of the fluorine atom requires one valence electron on each of their outermost shell.

One sodium atom establishes covalent connections with the central fluorine atom as a result, leaving the fluorine atom with three lone pairs. There are three lone pairs of electrons on the fluorine central atom that resists the bond pairs of the Na+—-F- bond. According to VSEPR theory, the Na+—-F- ionic bond pairs polarity lead the NaF molecule to take on the linear geometry structure.

The NaF molecule’s one Na+—-F- bonds are arranged in asymmetrical polarity order around the linear molecular geometry, giving rise to the NaF molecular shape. The NaF molecule has a linear molecular geometry because there is an electrical repulsion between the lone pairs of electrons in fluorine and one single ionic bond pair(Na-F) of the NaF molecule.

Lewis structure of NaF has dot electron representative structure. Valence electrons of atoms undergo orbitals mixing in the chemical reactions, giving new types of molecular species of NaF. The molecule is nothing but a bundle of valence electrons from the atoms. But it is converted to ionic bond pairs and lone pairs in the molecular structure.

Electronegative value Difference Calculation of NaF Molecule:

Fluorine and sodium Electronegative difference in NaF:

The fluorine atom has an electronegativity of 3.98, while sodium has an electronegativity of 0.93 in the NaF ionic molecule. The difference in electronegativity of fluorine and sodium can be estimated using the method below.

The electronegative value difference between fluorine and sodium in NaF molecule

Electronegativity value of fluorine= 3.98

Electronegativity value of sodium= 0.93

Difference of electronegativity value between fluorine and sodium in NaF molecule = 3.98 – 0.93 = 3.05. Electronegativity difference between Na-F ionic bond calculation of NaF molecule

The electronegative difference between fluorine and sodium is greater than 0.5. This indicated the bond polarity moves near to polar nature. Na-F ionic bond polarity in the NaF molecule is polar.

Because of this difference in electronegativity of fluorine and sodium atoms, the NaF molecule’s Na+—F- bond becomes nonpolar. The total net dipole moment of the NaF molecule is nonzero due to the cancellation of the bond dipole moment in the linear geometry due to the presence of three lone pairs of electrons. The electronegativity of an atom is the strength with which it may attract bound electron pairs to its side.

As a result, the Na-F bond’s dipole moment is higher due to the polarization of the bonds and four lone pairs of electrons on fluorine, and all Na-F bonds’ dipoles are arranged in the asymmetrical NaF molecular geometry. The NaF molecule has a nonzero net dipole moment.

The electron dot structure of the NaF molecule is also known as the NaF Lewis structure. It determines the number of outermost valence electrons as well as the electrons engaged in the NaF ionic molecule’s bond formation. The outermost valence electrons of the NaF molecule must be understood while constructing the Lewis structure of the molecule.

The fluorine atom is the middle element in NaF molecular geometry, with seven electrons in its outermost valence electron shell, whereas the sodium atom has one electron in its outermost valence electron shell. The sodium atom has one valence electron.

The NaF has a total of 8 valence electrons as a result of the foregoing above-said reasoning. With the core central fluorine atom, the one terminals with one sodium atom form ionic bonds, leaving the fluorine atom with four lone pairs in the middle of linear geometry.

Because three lone pairs on the terminal fluorine atoms create interaction with Na-F bond pairs(but it is negligible in the ground state of the NaF molecule). The bond angle of the Na-F bond in the linear molecular geometry is approximately 180 degrees. This angle is greater than the CH4 molecule bond angle. The Na-F bond length is 250 pm(picometer).

To sketch the NaF Lewis structure by following these instructions:

Step-1: NaF Lewis dot Structure by counting valence electrons on the fluorine atom

To calculate the valence electron of each atom in NaF, look for its periodic group from the periodic table. The halogen and alkaline metal group families, which are the 17th and 1st groups in the periodic table, are both made up of fluorine and sodium atoms respectively. In their outermost shells, sodium and fluorine have one and seven valence electrons respectively.

Calculate the total number of valence electrons in the NaF molecule’s outermost valence shell. The first step is to determine how many electrons are in the NaF Lewis structure’s outermost valence shell. An electron in an atom’s outermost shell is known as a valence electron. It is represented by dots in the NaF Lewis diagram. The NaF molecule’s core fluorine atom can be represented as follows:

Total outermost valence shell electron of fluorine atom in NaF= 7

Total outermost valence shell electron of sodium atom in NaF= 1

The NaF molecule has one central fluorine and one sodium atoms. Then the total outermost valence shell electrons can be calculated as follows

∴ Total outermost valence shell electrons available for NaF Lewis structure( dot structure) = 7+1*1= 8 valence electrons in NaF. calculation of total valence electron of NaF molecule

Choose the atom with the least electronegative value atom and insert it in the center of the molecular geometry of NaF. We’ll choose the least electronegative value atom in the NaF molecule to place in the center of the NaF Lewis structure diagram in this phase.

But in this case, sodium is the least electronegative than fluorine. Sodium loses one electron and forms sodium positive ions(Na+). So that fluorine stays in the central molecular structure. The electronegativity value in periodic groups grows from left to right in the periodic table and drops from top to bottom.

The first step is to put seven valence electrons around the sodium atom as given in the figure.

Step-2: Lewis Structure of NaF for counting valence electrons around the terminal sodium atoms

As a result, fluorine is the first atom in the periodic table’s halogen family group. Sodium is the third member of the alkaline metal family. It is the third element in the periodic table. The electronegative value of the fluorine atom is higher than that of the sodium atom in the NaF molecule. Furthermore, sodium has a one-electron limit since it is the less electronegative element in the NaF molecule.

In the NaF Lewis structure diagram, the fluorine atom can be the center atom of the molecule. As a result, central fluorine in the NaF Lewis structure, with one sodium atom arranged in a linear geometry.

Fluorine accepts one electron and forms a fluoride ion(F-). The total lone pair of electrons in the fluoride ion is eight. They are negatively charged.

Add valence electron around the fluorine atom, as given in the figure.

Step-3: Lewis dot Structure for NaF generated from step-1 and step-2

Connect the exterior and core central atom of the NaF molecule with one single Na-F bond. In this stage, use one sodium atom on the outside of the NaF molecule to the central fluorine atom in the middle.

Count how many electrons from the outermost valence shell have been used in the NaF structure so far. Na-F single bond carries two electrons because the fluorine atom is connected to one sodium atom by Na-F single bonds. Bond pairings of Na-F are what they’re called.

So, out of the total of 8 valence electrons available for the NaF Lewis structure, we used four electrons for the NaF molecule’s one Na-F single bond. The NaF molecule has three lone pairs of electrons in the central fluorine atom.

Place the valence electrons in the Na-F bond pair starting with the core fluorine, one sodium atom in the NaF molecule. In the NaF Lewis structure diagram, we always begin by introducing valence electrons from the central fluorine atom(in step 2). As a result, wrap around the central fluorine atom’s bond pair valence electrons first (see figure for step2).

The fluorine atom in the molecule gets only 8 electrons around its molecular structure. This central fluorine atom is octet stable. But it has three lone pairs. Fluorine gas(Br2) is a brownish liquid gas. Fluorine is very corrosive in nature. It is one of the very reactive chemical reagent.

Sodium metal is in a soft solid state at normal temperature and pressure. It is used as a reducing agent in the field of organic chemistry. It is highly flammable in nature. It is very reactive in water and alcohol. Water reacts with sodium metal and forms sodium hydroxide. Similarly, alcohol(such as methanol) reacted with sodium and forms sodium methoxide.

Fluorine requires 8 electrons in its outermost valence shell to complete the molecular octet stability, two electrons bond pairs in one Na-F single bond, and three lone pairs in the central fluorine atom. No lone pairs of electrons on the sodium atoms of the NaF molecule are placed in a linear geometry. Fluorine already shares 8 electrons to the one Na-F single bonds. Then place the valence electron in the sodium atoms, it placed around one electron on each atom(step-1). There are no valence electrons placed around one sodium atom as lone pair of electrons.

We’ve positioned 8 electrons around the one-terminal sodium atoms(step-3), which is represented by a dot, in the NaF molecular structure above. The fluorine atom completes its molecular octet stability in the NaF molecule because it possesses 2 electrons in its (one Na-F single ionic bond pairs) bond pairs with one sodium in the outermost valence shell.

Count how many outermost valence shell electrons have been used so far using the NaF Lewis structure. One electron bond pairs are shown as dots in the NaF chemical structure, whereas one single bond contains two electrons. The outermost valence shell electrons of the NaF molecule(bond pairs) are 2 as a result of the calculation. The total valence electron in a fluorine atom is 8.

So far, we’ve used 8 of the NaF Lewis structure’s total 8 outermost valence shell electrons. Three lone pairs of electrons on the fluorine atom in the linear or tetrahedral geometry of the NaF molecule.

Complete the middle NaF atom stability and, if necessary, apply a covalent bond. The central fluorine atom undergoes octet stability(due to one single bond pair of electrons).

The core atom in the NaF Lewis structure is fluorine, which is bonded to the one sodium atom by single bonds (one Na-F). With the help of one single bond, it already shares 8 electrons. As a result, the fluorine follows the octet rule and has 8 electrons surrounding it on the one terminal of the NaF molecule’s linear or tetrahedral geometry.

How to calculate the formal charge on fluorine and sodium atoms in NaF Lewis Structure?

Calculating formal charge on the fluorine of NaF molecule:

The formal charge on the NaF molecule’s fluorine central atom often corresponds to the actual charge on that fluorine central atom. In the following computation, the formal charge will be calculated on the central fluorine atom of the NaF Lewis dot structure.

To calculate the formal charge on the central fluorine atom of the NaF molecule by using the following formula:

The formal charge on the fluorine atom of NaF molecule= (V. E(F)– L.E(F) – 1/2(B.E))

V.E (F) = Valence electron in a fluorine atom of NaF molecule

L.E(F) = Lone pairs of an electron in the fluorine atom of the NaF molecule.

B.E = Bond pair electron in Br atom of NaF moleculecalculation of formal charge on fluorine atom in NaF molecule

The fluorine core atom (one single bond connected to one sodium atom) of the NaF molecule has seven valence electrons, three lone pairs of electrons(six electrons), and 2 bonding pairing valence electrons. Put these values for the fluorine atom in the formula above.

Formal charge on fluorine atom of NaF molecule = (7- 8-(0/2)) = -1

In the Lewis structure of NaF, the formal charge on the central fluorine atom is -1 (negative charge).

Calculating formal charge on the sodium atom of NaF molecule:

The formal charge on the NaF molecule’s sodium terminal atoms often corresponds to the actual charge on that sodium terminal atoms. In the following computation, the formal charge will be calculated on the terminal sodium atom of the NaF Lewis dot structure.

To calculate the formal charge on the terminal sodium atom of the NaF molecule by using the following formula:

The formal charge on the sodium atom of NaF molecule= (V. E(Na)– L.E(Na) – 1/2(B.E))

V.E (Na) = Valence electron in a sodium atom of NaF molecule

L.E(Na) = Lone pairs of an electron in the sodium atom of the NaF molecule.

B.E = Bond pair electron in H atom of NaF moleculecalculation of formal charge on sodium atom in NaF molecule

The sodium terminal atoms of the NaF molecule have one valence electron, no lone pairs of electrons(zero electrons), and two bonding pairing valence electrons(single bond). Put these values for the sodium atom in the formula above.

Formal charge on sodium atom of NaF molecule = (1- 0-(0/2)) =+1

In the Lewis structure of NaF, the formal charge on the terminal sodium atom is +1 (positive charge).

Summary:

In this post, we discussed the method to construct the NaF Lewis structure. First, the valence electrons are placed around the sodium atom and lose one electron. Then it becomes sodium positive ions. Second, place the valence electron on the fluorine atoms and the fluorine atom accepts one electron in its valence shell. Finally, when we combined the first and second steps. It gives NaF Lewis structure. Need to remember that, if you follow the above-said method, you can construct molecular dot structure very easily.