Cf4 Lewis Structure,Characteristics:13 Must To Know Facts


cf4 lewis structure and other important details regarding tetrafluoro methane is going to be discussed in this article.

Tetrafluoro methane, CF4 is a haloalkane or halo methane formed by replacing four hydrogen atoms of methane with fluorine atoms. It is a colorless, odourless gas which is used as refrigerant. It is an infalammable gas.

How to draw Tetrafluoromethane, CF4 Lewis structure ?

When two or more atoms join together a process called bond formation takes place. They do so by two ways. One is sharing of electrons and the latter is donating or accepting electrons. Since it is a big process we need to understand it in a simple way.

For this we use certain easy structures which shows how bond making takes place. This concept based structures are called Lewis dot structures. It is drawn by taking valence electrons in consideration. This electrons are denoted by dots and bonds through lines.

Electrons are denoted by dots so it is called Lewis dot structures. Here explains the fine details of depicting Lewis structure of tetra fluoro methane.

  • In First step we need to find the sum of valence electrons of every atom in tetra fluoro methane. Sum total of valence electrons in carbon and fluorine  is 4+7×4 = 32 electrons.
  • Draw the symbol of carbon atom enclosed with four fluorine in its four sides along with their valence electrons. The valence electrons linked with carbon also denoted by dots.
cf4 lewis structure
Valence electrons of CF4
  • In this last step we are going to see how this forms a bond. The carbon and fluorine shares their outer electrons and make four firm bonds. Those bonds are indicated by four lines in the structure.

Tetrafluoromethane, CF4 Resonance


Let’s discuss something about the organisation of electrons around the bonds and atoms. We can arrange these electrons in more than one way. Each organisation gives new structures. Those structures are called resonance structure and the phenomena is resonance. When we sketch these structures the bonds associated with the atoms should not be changed or removed.

If it do so the entire structure of that compound got destroyed. Usually double bonded compounds shows this phenomenon. In tetrafluoromethane it’s electrons can be arranged in only one way. So there is no more structures are possible for this molecule. So there is no resonating structure.

Tetrafluoromethane, CF4 Shape

Atoms joined together as a result of bond making always tends to occupy certain positions from the central atom. They do so for their stability to exist. That positioning of atoms in a bond assigns them certain shape. It can be linear, tetrahedral, pyramidal, triagonal depending upon the bonds made and atoms. The shape of tetrafluoromethane is tetrahedral.

Shape of CF4

Tetrafluoromethane, CF4 Formal charge

The positive, negative or neutral charge given to each atom in a molecule which formed a stable bond is its formal charge. The formal charge calculating equation is

Formal charge = valence electrons – No. of dots –  No. of bonds

Formal charge of carbon = 4-0-4 = 0

Formal charge of fluorine = 7-6-1 = 0

So the whole formal charge of atoms in CF4 is zero.

Tetrafluoromethane, CF4 Bond angle

The angle formed as a result of bond construction is called bond angle. It can be different depending upon the shape of molecule. Sometimes it’s values undergo slight variation due to other factors like bond length, lone pair of electrons, repelsion factors. Tetrafluoromethane makes an angle of 109.50 between carbon fluorine bonds.

Bond angle of CF4

Tetrafluoromethane, CF4 Octet rule

Based on octet rule there should be eight electrons in every atom’s outer shell to be in a stable state. Here fluorine has seven electrons and carbon has four in their outer shell. When they combine together each of them shares their electrons with each other. Then carbon get extra four electrons and each fluorine gets one electron. Thus carbon and fluorine get total eight electrons in total in their valence shell. So they obeys octet rule completely.

Tetrafluoromethane, CF4 Lone pair of electron

Sometimes all the valence electrons don’t go for bond building. Some of them will remain in its shell. Those electrons are called lone pair of electrons.

Tetrafluoromethane, CF4 Valence electrons

The electrons found in the valence shell of an atom which plays a crucial role in bond making is its valence electrons. It is usually found in outer shell of an atom.

Total valence electrons in CF4 = 4+7×4 = 32 electrons.

Tetrafluoromethane, CF4 Hybridisation

The merging of atomic orbitals of an atom to create fresh orbitals is called hybridization. The orbitals united is different in energy but the fresh ones formed is equal in its energy. There are different types of this process depending upon the orbitals got combined. They are sp, sp2,sp3,sp3d2, sp3d.

In tetrafluoromethane, five atoms exist. One Carbon and four fluorine atoms. Here carbon is the central or middle atom. Let’s discuss it’s hybridization.

Carbon (ground state)   1s2 2s2  2p2

Carbon (excited state)   1s2 2s2  2p3

Hybridisation in CF4

So one s and three p orbitals in carbon hybridise to form four sp hybrid orbitals. So here occurs sp3 hybridization. They are indistinguishable in shape. Then arrives the four fluorine atom with one electron in 2pz orbital and shares with the freshly formed sp3 orbitals. The shape of tetra fluoro methane is tetrahedral with an angle made is 109.50.

Solubility of  Tetrafluoromethane, CF4

The capability of a substance called solute to dissolve in a different substance called solvent is called solubility. The solute and solvent can be solid, liquid or gas. Water, ethanol, acetone, diethyl ether, benzene, hexane are some of the all time used solvents to dissolve substances. CF4 is partially miscible in water while get miscible in benzene and chloroform.

This is because if it get dissolved in water it has to break the hydrogen bonds between water molecules. More energy is needed for this to occur. As a result of less energy released during CF4 water solvation , CF4  not able to get dissolve in water.

About 18.8 mg/L Tetra fluoro methane is miscible in water at 200C.  But in the case of organic solvents the energy released as result of solvation of tetrafluoro methane it is much more than the older bonds between solvent molecules. So the older bonds can be easily broken and new one is formed.


Is Tetrafluoromethane, CF4  Ionic or not ?

Tetrafluoromethane is a covalent compound. Because each bond is made by sharing of electrons between carbon and fluorine.

Is Tetrafluoromethane, CF4  Acidic or not ?

Acidity is the talent of substance to accept electrons from other substances or acid is a substance which can donate protons of H ions into a solution. Basicity can be defined as donating OH ions or electrons to other substances. Tetra fluoro methane is neither acidic or basic.

It is a neutral compound. When it reacts water it forms hydrogen fluoride. Hydrogen fluoride is one of weak acid. So tetrafluoro methane is neutral but when dissolved in water release HF which is acidic in nature.

 Is Tetrafluoromethane, CF4 Polar or not ?

When there is a high electronegativity change is seen in between different bonds present in an atom their polarity will be different. Polarity commonly arrives due to the presence of an electronegative atom in a molecule. Most of the elements in halogen group were found to be always electronegative in nature.

Here in tetrafluoromethane there are four carbon fluorine bonds and their electronegativities are same. But the bonds in CF4 are equidistant to each other the dipole moment of each bond got cancelled and therefore it get non polar character.

Conclusion

Tetrafluoro methane,CF4 is a non polar, sp3 hybridised, covalent molecule which is acidic in water. It has 32 valence electrons out of which 12 lone pairs are present in fluorine. Its Lewis structure is also drawn here. The formal charge of CF4 is zero with tetrahedral shape and angle 109.50.

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