“A state or a condition of an atom or a molecule having positive and also negative charges, especially in case of magnetic or an electrical poles.”
Polarity, in general, refers to the physical properties of compounds such as boiling point, melting points, and their solubilities. The polarity of bonds mainly arises from the act between molecules and atoms with various electronegativities.
Moving on, usually, the term Polarity is used in areas like magnetism, electricity, and signalling of electronic devices. Consider an electromotive force (EMF) or an electric potential, acting between two points. Here the points or poles as they are commonly known as has more number of electrons than the other. The pole having more electrons possesses a negative polarity whereas the other end has a positive polarity.
Talking about polarity in Chemistry, well it is basically the separation of an electric charge which leads a molecule to have a positive and negative end.
Consider the below example
In an H-F bond, the fluorine atom is said to be more electronegative than that of the Hydrogen atom. The electrons eventually spend more time at the Fluorine atom. Hence this F atom slightly becomes negative whereas the Hydrogen atom tends to become slightly positive.
Polarity Of Molecules
The bond or the molecular polarities depend upon the electronegativities of the atoms or the molecules. A molecule is basically said to be either a polar molecule, non- polar molecule or ionic molecule.
- Polar Molecules: A polar molecule is usually formed when the one end of the molecule is said to possess more number of positive charges and whereas the opposite end of the molecule has negative charges, creating an electrical pole. When a molecule is said to have a polar bond, then the centre of the negative charge will be one side, whereas the centre of positive charge will be in the different side. The entire molecule will be a polar molecule.
- Non- Polar Molecules: A molecule which does not have the charges present at the end due to the reason that electrons are finely distributed and those which symmetrically cancel out each other are the non- polar molecules. In a solution, a polar molecule cannot be mixed with the non-polar molecule. For example, consider water and oil. In this solution, water is a polar molecule whereas oil behaves as a non-polar molecule. These two molecules do not form a solution as they cannot be mixed up.
Examples of Polar and Non-Polar Molecules
A molecule may be polar or non-polar. A non-polar molecule has a structure of its atoms lined up in a way that the orbital electrons in the outer region cancel out the electronegativity.
- In general, pyramid-shaped and V-shaped molecules are said to be polar. Whereas the Linear molecules are said to be non-polar in nature.
- Water is said to be a polar molecule due to the difference in the electronegativities between the oxygen atom and the hydrogen. Oxygen is a highly electronegative atom when compared to hydrogen.
- Fats, petrol, oil, gasoline are said to be non-polar molecules as they do not dissolve in water and nonpolar are insoluble in water.
- Glucose is one more example of a polar molecule based on the arrangement of the oxygen and hydrogen atoms in it.