Chemical Bonding: The Lewis Structure (Chapter 11) Part III

These flashcards cover key concepts from the lecture on chemical bonding and molecular geometry, focusing on VSEPR theory, hybridization, polarity, and bond types.

What does VSEPR theory help predict?

The shape of larger molecules based on electron group geometry.

What is molecular group geometry?

The 3D arrangement of electrons in a molecule.

How does the presence of lone pairs affect molecular shape?

Lone pairs impact the shape but not the arrangement of electron groups.

What is the electron group geometry of water (H2O)?

Tetrahedral due to four electron groups.

What is the molecular shape of methane (CH4)?

Tetrahedral.

When representing molecular geometry on paper, what is indicated by wedges and dashes?

Wedges indicate atoms in front of the plane, while dashes indicate atoms behind the plane.

What is the first step in predicting molecular geometry?

Draw the Lewis Structure.

How does one classify electron groups around a central atom?

As lone pairs or bonds.

What factors determine the polarity of a molecule?

Electronegativity differences and molecular geometry.

What results in a polar bond?

A difference in electronegativity between two atoms sharing electrons.

How is polarity determined in multi-atom molecules?

By the net electronegativity differences around the central atom.

What happens when electronegativity vectors around a central atom cancel each other out?

The molecule is considered nonpolar.

Describe a nonpolar covalent bond.

A bond between two atoms with similar electronegativities.

How do polar molecules behave in solvents?

They dissolve well in polar solvents like water.

What is an amphipathic molecule?

A molecule that has both polar and nonpolar regions.

What is valence bond theory?

A theory that explains the formation of bonds by electron interactions between atoms.

How does hybridization relate to bond formation?

Hybridization occurs to lower energy and create stable bonds.

What type of hybrid orbitals are formed with four electron groups?

sp3 hybrid orbitals.

What geometry do sp2 hybrid orbitals have?

Trigonal planar with bond angles of 120°.

In what scenario does sp hybridization occur?

When there are two electron groups present.

What is the bond composition of a triple bond?

One sigma bond and two pi bonds.

What defines a sigma bond?

It is formed by the end-to-end overlap of atomic orbitals.

Why are pi bonds considered weaker than sigma bonds?

Because side-to-side overlap is less efficient than end-to-end overlap.

What happens to bond rotation in the presence of pi bonds?

Rotation is restricted because pi bonds must break first.

What hybridization occurs with two electron groups?

sp hybridization.

What hybrid orbitals are created from the combination of one s and two p orbitals?

Three sp2 hybrids and one unhybridized p orbital.

What electron geometry is associated with sp hybridized atoms?

Linear geometry.

How many total hybrid orbitals are created during hybridization?

The total number of standard atomic orbitals equals the number of hybrid orbitals formed.

What is the effect of hybridization on molecular stability?

Hybridization generally leads to greater stability due to paired electrons.

In hybridization theory, what does the notation sp3 indicate?

One s orbital hybridized with three p orbitals.

What role do hybrid orbitals play in bond formation?

Hybrid orbitals form bonds with other atoms by overlapping.

How can you determine the number of hybrid orbitals formed?

By counting the number of atomic orbitals combined during hybridization.

________ cannot hybridize

hydrogen