Question

Find the type of chemical bond in MgCl2 and CH4 based on the

electronegativity values. Justify your answer.

(Hint: electronegativity:

Mg =1.31 Cl =3.16

C = 2.55 H =2.2)​

Answer 1

Explanation:

In MgCl 2, Magnesium has 12 electrons, and its electronic configuration can be written as 2,8,2. Thus Magnesium has two electrons in its outermost orbit or it can be said that Magnesium has 2 valence electrons.

In MgCl 2, each Chlorine atom has 17 electrons and its electronic configuration can be written as 2,8,7. Thus each Chlorine atom has seven electrons in its outermost orbit or it can be said that each Chlorine has 7 valence electrons.

Magnesium wants to give away its two valence electrons to complete its octet by having 8 electrons in its outermost orbit attaining the electronic configuration of its nearest inert gas Neon. And each chlorine atom wants to complete its octet by adding one more electron in its outermost orbit so that it can have 8 electrons in its outermost orbit attaining the electronic configuration of its nearest inert gas Argon.

So, we see that Magnesium wants to lose two electrons and each Chlorine atom wants to add one more electron in their outermost orbit

Thus, Magnesium transfers its two electrons to two Chlorine atoms (one electron to each Chlorine atom) and thus Magnesium obtains +2 charge and each chlorine atom acquires −1 charge and ionic bonds are formed between the atoms of the molecule.

An eletrovalent compound or ionic compound is formed when one atom in the compound transfers its electrons from itself to its neighboring atom.

In MgCl 2, Magnesium transfers its two electrons to its neighboring chlorine atoms, and forms two ionic bonds between the atoms.

Thus, MgCl

2 is an electrovalent compound or an ionic compound.

Answer 2

The type of chemical bonds in $\[MgC{l_2}\]$ and $\[C{H_4}\]$ based on the electronegativity values are ionic bond and covalent bond respectively.  

Explanation:

• The bond between two different atoms is ionic if the electronegativity difference between the bonded atoms is greater than $1.7$.
• If the electronegativity difference between the bonded atom is less than $1.7$, then the bond is covalent.
• In $\[MgC{l_2}\]$ , the electronegativity difference between Mg and Cl is $\[1.85\]$ ($\[3.16 - 1.31 = 1.85\]$). The value is more than 1.7. Therefore, the bond is an ionic bond.
• In $\[C{H_4}\]$, the electronegativity difference between C and H is $\[0.35\]$ ($\[2.55 - 2.2 = 0.35\]$). The value is less than 1.7. Therefore, the bond is a covalent bond.