Although it decomposes at room temperature, it can be stored indefinitely at -78 degrees Celsius. KrF2 reacts vigorously with Lewis acids to form KrF+ and Kr2F3+ salts. The molar mass of KrF2 is 121.795 g·mol−1. The density of KrF2 is 3.24 g cm−3. KrF2 is primarily used as an oxidizing and fluorinating agent because of its ability to oxidize even gold to its +5 oxidation state. It can be synthesized using the following methods:-
KrF2 Lewis Structure
KrF2 Lewis Structure
Before we write down the steps to draw the Lewis structure of KrF2, we will take a look as to how the Lewis structure of KrF2 should look like. The outermost electrons in the shell of an atom are termed valence electrons. We will use valence electrons as our main guide in drawing the Lewis structure. The Lewis structure of KrF2 shows that K is surrounded by 3 lone pairs of electrons and forms single bonds with each of the F atoms. Now we start looking at the steps required for drawing the Lewis structure:-
The highest valence factor. The highest number of bonding sites.
In KrF2, it’s obvious that Kr is the central atom. 3. Now we start arranging the electrons as lone pairs on each atom so that it forms a chemical bond. Since there are only two atoms of F, only 4 valence electrons are used up. 4. Now we start arranging the remaining valence electrons around each atom so that it completes its octet. When we finish the above step we notice that only 16 valence electrons have been used up. So, the remaining 6 valence electrons will act as lone pairs on the central atom Kr. This is an example of an exception to the octet rule. We notice that Kr can hold more than 8 valence electrons and this is due to the fact that elements below period 3 can have an expanded octet (more than 8 valence electrons) which serves as an exception to the octet rule. Hence Kr has 3 lone pairs on it and can hold more than 8 valence electrons. 5. Now you may ask why we didn’t convert the lone pairs into double or triple bonds? A valid question indeed! Remember that I had stated earlier that the best Lewis structure should ideally have each atom with a charge of 0. If we check the formal charge of each atom of KrF2 it turns out to be 0. However, if we convert the lone pairs into double or triple bonds, the formal charge is not the lowest possible. Hence that molecule will be quite unstable. Thus, this Lewis structure of KrF2 with 3 lone pairs has the highest stability with each atom having a formal charge of 0.
KrF2 Hybridization
KrF2 Hybridization
Hybridization is an important aspect when it comes to understanding the nature of the chemical bonds of a molecule. Hybridization helps us to find a more stable molecule by minimizing the energy of the molecule. The Hybridization of KrF2 is Sp3d. Hybridization of a molecule can found using two methods:-
KrF2 Molecular Geometry
KrF2 Molecular Geometry
The molecular shape as the name suggests is used to determine the shape of a molecule and its bond angles. The molecular shape is different from molecular geometry. Molecular geometry takes into account the electrons as well when determining the geometry. The geometry of KrF2 is trigonal bipyramidal. The molecular shape does take into account the lone pairs on the central atom. Thus, the molecular shape of KrF2 is linear. The bond angle formed between each atom is 180 degrees. The notation AXN can be used to determine the molecular shape of any molecule. A denotes the number of central atoms. X denotes the number of atoms that are bonded to the central atom. And finally, N denotes the number of lone pairs or the non-bonding electrons of the central atom. In KrF2, A=1 as Kr is the only central atom. X= 2 since there are 2 atoms of F attached to the central atom. N will be 3 as there are 3 lone pairs sitting on the central atom Kr. Thus using the above formula, we get the shape for KrF2 as AX2N3. If we check this formula in the VSEPR chart we see that KrF2 has a linear shape.
KrF2 Polarity
KrF2 Polarity
As mentioned above, the Kr is the central atom connected with 2 F atoms on both sides linearly forming a symmetrical shape of the KrF2 molecule. Moreover, both F atoms are identical having an equal electronegativity. As a result, both F atoms pull the charge with equal force and have equal charge distribution. Both dipoles act in opposite directions to cancel out each other. This results in a net-zero dipole moment. Thus, the KrF2 molecule is non-polar in nature.
Conclusion
In this article, we have discussed the Lewis structure, hybridization, and molecular shape of KrF2. So now you should be quite thorough with the basics of the KrF2 molecule. If you have any doubts regarding any of the points please feel free to talk to me. Learn well!
