Textbook Question
Determine the electron geometry, molecular geometry, and idealized bond angles for each molecule. In which cases do you expect deviations from the idealized bond angle?
a. CI4
b. NCl3
c. OF2
d. H2S
12. Molecular Shapes & Valence Bond Theory
Bond Angles
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which factor is primarily responsible for the difference in bond angles between carbon dioxide (CO_2) and water (H_2O)?
A
The number of hydrogen atoms bonded to the central atom
B
The presence of lone pairs on the central atom
C
The atomic mass of the central atom
D
The electronegativity of the oxygen atoms
Verified step by step guidance1
Identify the molecular geometry of both molecules: CO\_2 and H\_2O. CO\_2 is linear, while H\_2O is bent (angular).
Recall that the shape of a molecule is determined by the arrangement of electron pairs (bonding and lone pairs) around the central atom according to VSEPR (Valence Shell Electron Pair Repulsion) theory.
For CO\_2, the central carbon atom has two double bonds and no lone pairs, leading to a linear shape with bond angles of 180°.
For H\_2O, the central oxygen atom has two single bonds and two lone pairs. Lone pairs repel more strongly than bonding pairs, causing the bond angle to decrease from the ideal tetrahedral angle (109.5°) to about 104.5°.
Therefore, the primary factor responsible for the difference in bond angles is the presence of lone pairs on the central atom, which affect the molecular geometry by repelling bonding pairs and altering bond angles.
Related Videos
Related Practice
