The positive and negative charge centers in the molecule do not overlap, and the charge distribution is uneven and asymmetrical from the point of view of the entire molecule, such molecules are polar molecules. Generally, it can be judged from the structure and solubility: the polarity of substances with exposed hydroxyl groups, exposed carboxyl groups, and exposed amino groups may be very high; then the solubility test shows that the polarity of the solvent is generally consistent with the polarity of the substance.
Polar molecules refer to molecules whose positive and negative charge centers do not overlap. Diatomic molecules bound by polar bonds must be polar molecules. Polyatomic molecules bound by polar bonds depend on the structure. For example, CH4 is not a polar molecule. The composition For ABn-type compounds, if the valence of the central atom A is equal to the ordinal number of the group, the compound is a non-polar molecule.
What is molecular polarity
Molecular polarity means that the positive and negative charge centers in the molecule do not overlap, resulting in the uneven distribution of charges. The polarity of the covalent bond is caused by the different electronegativity of the two atoms forming the bond. Electronegative Atoms with high polarity will pull the shared electron pairs to its side, making the charge unevenly distributed. The polarity of the bond can be measured by the difference in electronegativity between two atoms. The difference between 0.4 and 1.9 is typical polar covalent bond.
What is polarity?
Objects exhibiting opposite inherent properties or forces in opposite parts or directions, direction or attraction to a particular thing, if the charge is unevenly distributed, the bond or molecule is said to be polar; if uniform, it is called non-polar , Some physical properties of substances (such as solubility, melting and boiling points, etc.) are related to the polarity of molecules, and the specific positive and negative states of the two poles or electrification (such as objects).