Related Problems with Solutions
Problem 14 : Discuss the VSEPR (Valence Shell Electron Pair Repulsion) theory and how it predicts the molecular geometry of molecules. Determine the molecular geometry of methane (CH₄) using VSEPR.
Solution :
VSEPR theory predicts the molecular geometry of molecules based on the repulsion between electron pairs around the central atom. To determine the molecular geometry, follow these steps for methane (CH₄):

Count the total number of valence electrons: C has 4, and each H has 1. Total = 4 (C) + 4 (H) = 8 electrons.

Determine the central atom: In CH₄, carbon (C) is the central atom.

Predict the electron pair geometry: For CH₄, there are 4 bonding pairs (CH bonds) around carbon. This corresponds to a tetrahedral electron pair geometry.

Predict the molecular geometry: In CH₄, there are no lone pairs on carbon. The molecular geometry matches the electron pair geometry, so it is also tetrahedral.