How to draw BeCl2 Lewis Structure? - Science Education and Tutorials

Drawing BeCl2 Lewis Structure is very easy. Here in this post, we described step by step method to construct BeCl2 Lewis Structure.

Table of Contents

Key Points To Consider When Drawing The BeCl2 Lewis Structure

A three-step approach for drawing the BeCl2 Lewis structure can be used. The first step is to sketch the Lewis structure of the BeCl2 molecule, to add valence electron around the Beryllium atom; the second step is to valence electron to the two chlorine atoms, and the final step is to combine the step1 and step2 to get the BeCl2 Lewis Structure.

The BeCl2 Lewis structure is a diagram that illustrates the number of valence electrons and bond electron pairs in the BeCl2 molecule. The geometry of the BeCl2 molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory), which states that molecules will choose a BeCl2 geometrical shape in which the electrons have from one another.

Finally, you must add their bond polarities to compute the strength of the Be-Cl bond (dipole moment properties of the BeCl2 molecule). The Beryllium-Chlorine bonds in beryllium chloride(BeCl2), for example, are polarised toward the more electronegative chlorine, and because both bonds have the same size and opposite to each other, their sum is zero due to the BeCl2 molecule’s bond dipole moment, and the BeCl2 molecule is classified as a nonpolar molecule.

The molecule of beryllium chloride (with linear geometry) is tilted at 180 degrees and has a difference in electronegativity values between chlorine and beryllium atoms, with beryllium’s pull being less than chlorine’s terminal in the BeCl2 molecule. As a result, it has no dipole moment. The BeCl2 molecule has no dipole moment due to an equal charge distribution of negative and positive charges.

BeCl2 Lewis Structure:

The central atom is beryllium, which is bordered on two terminals with chlorine atoms. Beryllium has two outermost valence electrons, indicating that it possesses two electrons in its outermost shell, whereas chlorine only has seven valence electrons in its outermost shell. To complete the octet of the chlorine atom, a chlorine terminal atom requires one electron. If you’re interested in learning more about the chlorine octet rule, please see in our previous post.

Two chlorine atoms establish covalent connections with the beryllium atom as a result, leaving the beryllium atom without any lone pairs. There are no lone pairs on the beryllium central atom that resist the bond pairs of the two Be-Cl. According to VSEPR theory, no electronic repulsion leads the BeCl2 molecule to take on a linear molecular shape like NO2+ and CS2.

The BeCl2 molecule’s Be-Cl bonds are arranged in a symmetrical order around the linear geometry, giving rise to the linear BeCl2 shape. The BeCl2 molecule has a linear molecular geometry because there is no electrical repulsion between them.

Electronegative Difference Calculation BeCl2 Molecule:

Beryllium has an electronegativity of 1.57, while chlorine has an electronegativity of 3.16 in the BeCl2 molecule. The difference in electronegativity can be estimated using the method below.

The electronegative value difference between beryllium and chlorine
Electronegativity value of beryllium = 1.57
Electronegativity value of chlorine= 3.16
Difference of electronegativity value between beryllium and chlorine= 3.16 – 1.57 =1.59
Electronegativity difference between Be-Cl bond calculation of BeCl2 molecule

Due to the difference in electronegativity value of greater than 0.5, the Be-Cl bond of the BeCl2 molecule becomes polar. Because of this difference in electronegativity, the BeCl2 molecule’s Be-Cl bond becomes polar. The electronegativity of an atom is the strength with which it may attract bound electron pairs to its side. The polarity of BeCl2 is discussed in our previous post.

As a result, the Be-Cl bond’s dipole moment is high due to the polarization of the bonds, and all Be-Cl bonds’ dipoles are faced opposite to each other in the linear geometry. The BeCl2 molecule’s total dipole moment is predicted to be 0 D. It has a partial negative charge for chlorine atoms and a partial positive charge for the central beryllium atom.

The electron dot structure of the BeCl2 molecule is also known as the BeCl2 Lewis structure. It determines the number of outermost valence electrons as well as the electrons engaged in the BeCl2 molecule’s bond formation. The outermost valence electrons of the BeCl2 molecule must be understood while considering the Lewis structure of the molecule.

The beryllium atom is the middle element in BeCl2 molecular geometry, with two electrons in its outermost valence electron shell, whereas the chlorine atom has seven electrons in its outermost valence electron shell.

The BeCl2 molecule has a total of 16 valence electrons as a result of the foregoing reasoning. With the core central beryllium atom, the two terminal chlorine atoms form covalent bonds, leaving the beryllium atom with no lone pairs on it.

The linear geometry and structure of the BeCl2 molecules are similar to that of the carbon disulfide (CS2) molecule because no lone pairs of central beryllium atom create interaction with Be-Cl bond pairs. The bond angle of the Cl-Be-Cl bond is approximately 180 degrees. The Be-Cl bond length is 181 pm(picometer).

To sketch the BeCl2 Lewis structure by following these instructions:

Step-1: BeCl2 Lewis Structure

To calculate the valence electron of each atom in BeCl2, look for its periodic group from the periodic table. The alkaline earth metal and halogen families, which are the second and 17th groups in the periodic table, are both made up of beryllium and chlorine atoms. In their outermost shells, beryllium and chlorine have two and seven valence electrons, respectively.

Because beryllium and chlorine are members of the periodic table’s alkaline earth metals and halogen family groups, their valence electrons are two and seven, respectively.

Calculate the total number of electrons in the BeCl2 molecule’s outermost valence shell. The first step is to determine how many electrons are in the BeCl2 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 BeCl2 Lewis diagram. The BeCl2 molecule’s core carbon atom can be represented as follows:

Total outermost valence shell electron of beryllium atom in BeCl2= 2
Total outermost valence shell electron of chlorine atom in BeCl2= 7
The BeCl2 molecule has one central beryllium atom and two chlorine atoms. Then the total outermost valence shell electrons can be calculated as follows
∴ Total outermost valence shell electrons available for BeCl2 Lewis structure( dot structure) = 2 +2*7= 16 valence electrons in BeCl2
calculation of total valence electron of BeCl2 molecule

Choose the atom with the least electronegative value atom and insert it in the center of the molecular geometry of BeCl2. We’ll choose the least electronegative value atom in the BeCl2 molecule to place in the center of the BeCl2 Lewis structure diagram in this phase. The electronegativity value in periodic groups grows from left to right in the periodic table and drops from top to bottom.

Step-2: BeCl2 Lewis Structure

As a result, Beryllium is the first atom in the periodic table’s alkaline earth metal family group. Chlorine is the second member of the halogen family. The electronegative value of a beryllium atom is lower than that of a chlorine atom. Furthermore, Beryllium has a two electrons limit since chlorine is the most electronegative element in the BeCl2 molecule.

In a BeCl2 Lewis structure diagram, the beryllium atom can be the center atom. As a result, central beryllium in the BeCl2 Lewis structure, with all two chlorines arranged in the two terminal of linear geometry.

Step-3: BeCl2 Lewis Structure

Connect the exterior and core central atom of the BeCl2 molecule with two single bonds (Be-Cl). In this stage, use two single bonds to connect all two chlorine atoms on the outside of the BeCl2 molecule to the central beryllium atom in the middle.

Count how many electrons from the outermost valence shell have been used in the BeCl2 structure so far. Each Be-Cl bond carries two electrons because each beryllium atom is connected to two chlorine atoms by two Be-Cl bonds. Bond pairings are what they’re called.

So, out of the total of 16 valence electrons available for the BeCl2 Lewis structure, we used 4 for the BeCl2 molecule’s two single (Be-Cl) bonds. The BeCl2 molecule has no lone pair electrons in the center beryllium. We don’t need to put the extra electron in the molecular geometry of Becl2.

Place the valence electrons in the Be-Cl bond pairs starting with the core beryllium and two chlorine atoms in the BeCl2 molecule. In the BeCl2 Lewis structure diagram, we always begin by introducing valence electrons from the central beryllium atom. As a result, wrap around the central beryllium atom’s bond pair valence electrons first.

Beryllium requires 4 electrons in its outermost valence shell to complete the molecular stability. Beryllium already shares 4 electrons thanks to the two single bonds. Then place the valence electron in the chlorine atom, it placed around seven electrons. Totally, 12 valence electrons placed on the two chlorine atoms of the BeCl2 molecule.

We’ve positioned four electrons around the central beryllium atom, which is represented by a dot, in the BeCl2 molecular structure above. The beryllium atom completes its molecular stability in the BeCl2 molecule because it possesses 4 electrons in its outermost valence shell.

Count how many outermost valence shell electrons have been used so far using the BeCl2 Lewis structure. Four electrons are shown as dots in the BeCl2 chemical structure, whereas two single bonds each contain two electrons. The outermost valence shell electrons of the BeCl2 molecule are 4 + 12= 16 as a result of the calculation.

So far, we’ve used 16 of the BeCl2 Lewis structure’s total eight outermost valence shell electrons.

Complete the middle beryllium atom stability and, if necessary, apply a covalent bond. The core atom in the BeCl2 Lewis structure is beryllium, which is bonded to the chlorine atoms by two single bonds (Be-Cl). With the help of two single bonds, it already shares four electrons. As a result, chlorine follows the octet rule and has eight electrons surrounding it on the two terminals of BeCl2.

Watch the Video to draw BeCl2 Lewis Structure:

How to calculate the formal charge in BeCl2 Lewis Structure?

The formal charge on the BeCl2 molecule’s beryllium central atom often corresponds to the actual charge on that beryllium central atom. In the following computation, the formal charge will be calculated on the central beryllium atom of the BeCl2 Lewis dot structure.

To calculate the formal charge on the central beryllium atom of the BeCl2 molecule by using the following formula:
The formal charge on the beryllium atom of BeCl2 molecule= (V. E(Be)– L.E(Be) – 1/2(B.E))
V.E (Be) = Valence electron in beryllium atom of BeCl2 molecule
L.E(Be) = Lone pairs of an electron in the beryllium atom of the BeCl2 molecule.
B.E = Bond pair electron in Be atom of BeCl2 molecule
calculation of formal charge on beryllium atom in BeCl2 molecule

The beryllium core atom (two single bonds connected to chlorines) of the BeCl2 molecule has two valence electrons, zero lone pair electrons, and four bonding electrons. Put these values for the beryllium atom in the formula above.

Formal charge on beryllium atom of BeCl2 molecule = (2- 0-(4/2)) =0

In the Lewis structure of BeCl2, the formal charge on the central beryllium atom is zero.

Summary:

In this post, we discussed the method to construct the BeCl2 Lewis structure. Need to remember that, if you follow above said method, you can construct molecular dot structure very easily.