Is SeF4 Polar or Nonpolar? [Quick overview]

Is SeF4 polar or nonpolar?

SeF4 is the molecular formula for the chemical compound selenium tetrafluoride. This chemical is an inorganic compound. It is a colorless liquid in nature that reacts highly with water. This compound is used as a fluorinating reagent in inorganic synthesis. This compound can be in a liquid stage rather than gas stage. This compound is used to add fluorine to another chemical compound as it acts as a fluorinating agent.

Selenium tetrafluoride consists of selenium and fluorine. Selenium tetrafluoride has a molecular mass of 154.954 g/mol and is calculated as below:

Molecular mass of SeF4 = 1*78.96 (moll mass of selenium) + 4*18.984032 (moll mass of fluorine) = 154.954 g/mol.

What are polar and nonpolar molecules?

In simple words polar means those oppositely charged whereas nonpolar means those equally charged. The distribution of electric charge around chemical groups, molecules or atoms is known as polarity.

There are two types of molecules that is polar and nonpolar molecules. Some molecules can be easy to find out where as some possesses both the characters of polar and nonpolar molecules and can be very tricky to find out.

Polar molecules

Polar molecules are those molecules that occur when there is an electronegativity difference between two bonded atoms. When the two atoms do not share electrons equally in a covalent bond polar molecules are formed.

A dipole is formed when the molecules are carrying a slight positive charge and other carrying a slight negative charge. This is usually formed when there is a difference between electronegativity values of each atom

By looking at the electronegativity at a table we are most likely to find out about which bond the atoms are most likely to form. If the electronegativity difference is anywhere between 0.4 to 2.0 then those atoms would form a polar bond.

Examples of polar molecules:

  • Ammonia -NH3
  • Water – H2O
  • Ethanol – C2H6O
  • Sulfur dioxide – SO2
  • Hydrogen sulfide – H2S

Nonpolar molecules

In a nonpolar molecule there is no positive or negative charge poles. These molecules are formed when the electrons are evenly distributed. When the molecules share electrons equally in a covalent bond the molecules do not get electrically charged.

When two atoms have the same or similar electronegativity nonpolar molecules will not get formed. Unlike polar bond nonpolar bonds share electrons equally. If the electronegativity is less than 0.5 the bond is considered to be a nonpolar. The electrons get shared equally because the electronegativity difference between the two atoms is zero.

Some examples of nonpolar bonds:

  • Carbon dioxide – CO2
  • Benzene – C6H6
  • Methane – CH4
  • Ethylene – C2H4
  • Most organic compounds

Why is SeF4 a polar molecule?

Polar molecules can be defined as the presence of polar bonds within the molecules. Poplar molecules do not have symmetrical structure meaning that they have irregular geometry.  When two atoms do not share electrons equally in a covalent bond polar molecules are formed. During the presence of an electric field the moments of polar molecule tend to align together and on the absence of electric field the moments get randomly spread.

SeF4 is a polar molecule due to its trigonal bipyramid geometry. This asymmetric shape of the molecule results in the value of dipole moment which causes the bond to be polar. Fluorine being more electronegative than selenium also causes the unequal distribution of charge across the molecule.

Is SeF4 polar or nonpolar?

Electronegativity difference:

Electronegativity difference is defined as the propensity of a molecule to draw in solitary sets of electrons towards itself between two atoms is between 0.5 to 2.0 it is considered to be a polar bond.

In SeF4 molecule this bond consists of fluorine and selenium. Fluorine having an electronegativity value of 4.0 and selenium having an electronegativity value of 2.55 causes the electronegativity value between them to be 1.45 making this bond a polar bond n nature.

Lewis structure/ molecular geometry:

Polar molecules are those molecules that occur when there is an electronegativity difference between two bonded atoms. When the two atoms do not share electrons equally in a covalent bond polar molecules are formed.

When the arrows are of different length and if the arrows do not balance each other and are asymmetrical in shape then the molecules are considered to be polar. This bond has a geometry of trigonal bipyramid shape which is caused because of the selenium central atom having one lone pair on equatorial position and 4 bonded pairs being attached to it.

Dipole moments:

A dipole is formed when the molecules are carrying a slight positive charge and other carrying a slight negative charge. This is usually formed when there is a difference between electronegativity values of each atom

Dipole can be known as molecules with two poles. A dipole moment is the measurement done to separate the two opposite electrically charged poles. A dipole moment can occur between two ions in an ionic bond or between two atoms in a covalent bond.

This bond contains two pairs of electrons and two polar bonds which causes a net dipole moment on the molecules due to their geometrical arrangement.

Solubility principle:

According to the principle of solubility stating that likes dissolves in likes meaning that that polar molecules dissolves in polar solvents and nonpolar molecules dissolves in nonpolar solvent.

Properties

  • It has a molecular mass of 154.954 g/mol.
  • It appears as a colorless liquid.
  • It has a boiling point of 101˚c.
  • It has a melting point of -13.2˚c.

Conclusion

Polar molecules can be defined as the presence of polar bond within a molecule. Polar molecules do not have symmetrical structure i.e. they have an irregular shape. When two atoms do not share electrons equally in a covalent bond polar molecules are formed.

Polar molecules are those molecules that occur when there is an electronegativity difference between two bonded atoms. When the two atoms do not share electrons equally in a covalent bond polar molecules are formed. If the electronegativity difference is between 0.4 and 2.0 the atoms forms a polar covalent bond and since, the electronegativity difference in this bond is 1.45 causing this bond to be a polar bond.

 

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