Molecular Shapes and VSEPR Theory

The video explains how to predict molecular shapes using VSEPR theory. It covers examples like methane, ammonia, water, formaldehyde, and carbon dioxide, detailing their electron and molecular geometries. The video emphasizes counting electron groups around the central atom to determine shapes and angles, highlighting differences between electron and molecular geometries.

What theory is used to predict the three-dimensional shapes of molecules?

• Quantum Mechanics

• VSEPR Theory

• Bohr's Model

• Molecular Orbital Theory

What is the shape of a methane molecule according to VSEPR theory?

• Linear

• Trigonal Planar

• Tetrahedral

• Bent

Why do we refer to 'electron groups' instead of just 'bonds' in VSEPR theory?

• Because it includes lone pairs and multiple bonds

• Because it is a simpler term

• Because it only applies to single bonds

• Because it is a historical term

What is the molecular geometry of ammonia?

• Trigonal Pyramidal

• Trigonal Planar

• Linear

• Tetrahedral

How does the presence of a lone pair affect the bond angles in ammonia?

• It makes the molecule linear

• It has no effect

• It decreases the bond angles

• It increases the bond angles

What is the molecular shape of a water molecule?

• Bent

• Trigonal Planar

• Tetrahedral

• Linear

Why is the bond angle in water smaller than in ammonia?

• Because water has fewer lone pairs

• Because water has more lone pairs

• Because water is a smaller molecule

• Because water is a larger molecule

What is the electron geometry of formaldehyde?

• Tetrahedral

• Trigonal Planar

• Linear

• Bent

What is the molecular shape of carbon dioxide?

• Linear

• Bent

• Tetrahedral

• Trigonal Planar

Why is carbon dioxide linear while water is bent?

• Carbon dioxide has more electron groups

• Water has fewer electron groups

• Water has more electron groups

• Carbon dioxide has fewer electron groups