Study Guide Chapter 5: Chemical Bonding and Molecular Geometry

This set of flashcards covers key concepts and definitions related to molecular geometry, polarity, bonding, and Lewis structures based on the study guide from a chemistry lecture.

What is VSEPR theory used for?

To predict the shape of molecules based on the idea that electron pairs around a central atom repel each other and arrange to minimize repulsion.

What is the steric number formula?

Steric number = number of bonding pairs + number of lone pairs.

What is the electronic geometry for SN=4?

Tetrahedral.

How do lone pairs affect molecular geometry?

Lone pairs affect the shape formed by the atoms in the molecule, changing the geometry from what it would be with only bonding pairs.

What is a polar covalent bond?

A bond formed when two atoms share electrons unequally due to a difference in electronegativity.

How can you determine if a molecule is polar or non-polar?

By drawing the Lewis structure, determining the molecular geometry, identifying bond dipoles, and observing if the dipoles cancel.

What is the effect of polarity on boiling points?

Polar molecules generally have higher boiling points due to stronger dipole-dipole interactions, while nonpolar molecules have lower boiling points due to weaker London dispersion forces.

What are the rules for naming binary ionic compounds?

The metal (cation) is named first using the element name, and the nonmetal (anion) is named second using the root + -ide suffix.

What does the octet rule state?

Atoms tend to gain, lose, or share electrons to achieve a full octet (8 valence electrons) in their outer shell.

What are diatomic molecules?

Molecules composed of two identical atoms.

List the diatomic elements.

Bromine (Br2), Iodine (I2), Nitrogen (N2), Chlorine (Cl2), Hydrogen (H2), Oxygen (O2), Fluorine (F2).

What is electronegativity?

The ability of an atom to attract electrons in a bond.

What is the formula for calculating formal charge?

Formal charge = valence electrons - (lone pair electrons + bonding electrons/2).

What is bond order?

Bond order = number of bonding pairs / number of bonding regions; higher bond order means a stronger, shorter bond.

What are resonance structures?

Structures that represent situations where more than one valid Lewis structure exists for a molecule.

What's an exception to the octet rule regarding incomplete octet?

Elements such as Beryllium and Boron may not have a complete octet.

What is meant by hypervalency?

When elements in period 3 or beyond have more than 8 electrons in their valence shell.