Limitations of VSEPR Theory

The video revisits VSEPR theory, explaining its application in predicting molecular geometries. It highlights the theory's limitations, especially with larger central atoms like sulfur and tellurium, where hybridization is minimal or absent. The video uses water, hydrogen sulfide, and hydrogen telluride as examples to illustrate these concepts, emphasizing that VSEPR is more applicable to smaller atoms like carbon, nitrogen, and oxygen.

What is the primary purpose of VSEPR theory?

• To predict the color of molecules

• To explain molecular geometries

• To determine the mass of atoms

• To calculate the speed of chemical reactions

How does VSEPR theory describe the geometry of a water molecule?

• Linear with a bond angle of 180 degrees

• Trigonal planar with a bond angle of 120 degrees

• Tetrahedral electron domain geometry with a bent shape

• Octahedral with a bond angle of 90 degrees

Why does hydrogen sulfide have a different bond angle compared to water?

• Due to the presence of more lone pairs in sulfur

• Because sulfur is smaller than oxygen

• Because sulfur is larger, reducing electron pair repulsion

• Due to the absence of hybridization in sulfur

What is the observed bond angle in hydrogen telluride?

• 90 degrees

• 92.1 degrees

• 109.5 degrees

• 104.5 degrees

Why does tellurium not undergo hybridization in hydrogen telluride?

• Because its valence electrons are in the n equals 2 shell

• Due to the large atomic radius and minimal electron repulsion

• Because it forms ionic bonds instead of covalent bonds

• Due to the presence of d-orbitals

What happens to VSEPR theory when applied to molecules with large central atoms?

• It predicts new molecular shapes

• It becomes more accurate

• It remains unchanged

• It quickly becomes less applicable

In which type of molecules does VSEPR theory still have abundant application?

• Inorganic molecules with transition metals

• Molecules with noble gases

• Molecules with large central atoms

• Organic molecules with second-period elements