Question

The bond angle in ${\mathrm{H}}_2\mathrm{O}\mathrm{is}104.5^{°}.$ This fact can be explained with the help of ?

• A. VSEPR theory
• B. Molecular orbital theory
• C. Electronegativity difference between Oxygen and Hydrogen atoms
• D. Presence of Hydrogen bond

Answer 1

The correct option is A

VSEPR theory

Explanation for the correct option:

Option(A):VSEPR theory

• VSEPR Theory is used to predict the shape of any given molecule from the electron pairs that surround the central atoms of the molecule.
• According to this theory, the atoms tend to arrange themselves in a manner in which this electron pair repulsion is minimalized, which in turn determines the geometry and shape of the resulting molecule.
• In the case of ${\mathrm{H}}_2\mathrm{O}$the Oxygen, the atom has 6 electrons of which two of them are bonded with a hydrogen atom leaving two lone pairs of electrons.
• The presence of these 2 lone pairs represents the bond angle of ${\mathrm{H}}_2\mathrm{O}$to be $104.5^{°}$, which can be only explained by the valence shell electron pair repulsion theory (VSEPR).

Explanation for the incorrect option:

Option(B):Molecular orbital theory

• The molecular orbital theory does not help in explaining the bond angle of any molecule.
• hence, the given option is the incorrect one.

Option(C): Electronegativity difference between Oxygen and Hydrogen atoms

• The electronegativity difference between Oxygen and Hydrogen atoms does not explain the bond angle in ${\mathrm{H}}_2\mathrm{O}\mathrm{is}104.5^{°}.$
• Thus, the given option does not represent the correct option.

Option(D): Presence of Hydrogen bond

• The bond angle in ${\mathrm{H}}_2\mathrm{O}$can't be explained by the presence of a Hydrogen bond.
• Hence, the given option does not coincide with the given option.

Hence, the given fact can be explained with the help of the VSEPR theory.