Question
Question: How does bonding affect molecular geometry?...
How does bonding affect molecular geometry?
Solution
We know that the force that holds together the different atoms in a molecule is termed as chemical bond. There are two types of chemical bonding that is ionic bonding and covalent bonding.
Complete step by step answer:
Let’s discuss the geometries of the molecules. On the basis of VSEPR theory, the covalent molecules can have two types of geometries which are regular and irregular in nature.
Now we understand regular geometry in detail. The geometry of a molecule is regular if the central atom is surrounded by all bond pairs of electrons with similar atoms. Repulsive interactions in the bond pairs mutually balance each other. However, the actual geometries are different from different molecules.
For example, CH4, BeF2etc.
Now we understand irregular geometry in detail. In case the central atom in a covalent molecule is surrounded by either bond pairs with different atoms or both bond pairs and lone pairs of electrons, then the repulsive interactions in such pairs do not mutually balance each other. Under such conditions, the geometries of the molecules are said to be irregular or distorted.
For example, CHCl3, H2O (Two lone pair), NH3(One lone pair)
Note: It is to be remembered that Valence Shell Electron pair repulsion (VSEPR) theory was given by Gillespie and Nyholmn to predict the observed shapes of the molecules in which the atoms are linked together by covalent bonds only. Some of the main features of VSEPR theory are,
1)The shape of a molecule depends on the number of electron pairs (bonded or non bonded) around the central atom.
2)There is repulsion between the electron pairs around the central atom.
3)The electronic pairs take such positions in space where repulsive interactions are minimum
4)A multiband is treated as if it is a single bond and the electron pairs which constitute the bond may be regarded as single pairs.