General Chemistry Chapter 1 Review

Flashcards covering the fundamental concepts of organic chemistry including bonding theories, structural representations, and physical properties.

Organic Chemistry

The branch of chemistry that studies the structure, properties, reactions, and synthesis of carbon-based compounds.

Electronegativity

How strongly an atom pulls electrons toward itself in a bond, used to determine if a bond is polar and which atom carries a $\delta-$ or $\delta+$ charge.

Octet Rule

The tendency of atoms to form bonds in order to fill their outer electron shell, usually reaching $8$ electrons to become more stable.

Nonpolar Covalent Bond

A bond where the electronegativity difference ($\Delta EN$) between atoms is between $0.0$ and $0.4$.

Polar Covalent Bond

A bond where the electronegativity difference ($\Delta EN$) between atoms is between $0.5$ and $1.7$.

Ionic Bond

A bond where the electronegativity difference ($\Delta EN$) between atoms is between $1.8$ and $3.3$.

Lewis Structure

A blueprint of a molecule showing all atoms, all shared electron bonds, and all lone pairs of unshared electrons.

Formal Charge

The charge an atom would have if all bonding electrons were shared equally, calculated as: $\text{Valence electrons} - \text{Lone pair electrons} - \frac{1}{2}(\text{Shared electrons})$.

Bond-Line Structure

A simplified drawing style for organic molecules where carbon atoms are represented as corners or ends of lines, and hydrogens attached to carbons are not shown.

Constitutional Isomers

Different compounds that share the same chemical formula but have different atom connectivity.

Atomic Orbital

A region in space around a nucleus with a high probability of finding an electron, described by the square of a wavefunction ($\psi^2$).

Node

A region in an orbital where the wavefunction is equal to zero and there is zero electron density.

Aufbau Principle

The rule stating that electrons must fill the lowest energy orbitals first.

Pauli Exclusion Principle

The rule stating that each orbital can hold a maximum of two electrons with opposite spins.

Hund’s Rule

The rule stating that when filling orbitals of equal energy, one electron is placed in each orbital before they are paired.

Valence Bond Theory

A theory describing a covalent bond as the sharing of electron density resulting from the constructive interference of atomic orbitals.

Sigma ($\sigma$) Bond

A bond formed by end-to-end overlap of orbitals with electron density concentrated on the bond axis and possessing circular symmetry.

Pi ($\pi$) Bond

A bond formed by side-by-side overlap of $p$ orbitals with electron density concentrated above and below the bond axis, preventing free rotation.

Molecular Orbital (MO) Theory

A theory using the Linear Combination of Atomic Orbitals (LCAO) to form new orbitals that belong to the entire molecule.

Bonding Molecular Orbital

A lower-energy orbital formed by constructive interference where electron density builds up between the nuclei to stabilize the molecule.

Antibonding Molecular Orbital

A higher-energy orbital formed by destructive interference characterized by a node between the nuclei that destabilizes the molecule.

HOMO

Highest Occupied Molecular Orbital; the highest-energy molecular orbital that contains electrons.

LUMO

Lowest Unoccupied Molecular Orbital; the lowest-energy molecular orbital that is empty.

Hybridization

A mathematical model that mixes atomic orbitals to create new hybrid orbitals (like $sp^3$, $sp^2$, or $sp$) to match observed molecular shapes.

Steric Number

The sum of the number of bonded atoms and the number of lone pairs on a central atom, used to determine hybridization.

VSEPR Theory

Valence Shell Electron Pair Repulsion theory; states that electron pairs around a central atom repel each other to stay as far apart as possible.

Dipole Moment ($\mu$)

A measure of polarity determined by the formula $\mu = \delta \times d$, where $\delta$ is partial charge and $d$ is distance.

London Dispersion Forces

Temporary dipole-dipole forces present in all molecules caused by the constant motion of electrons.

Hydrogen Bonding

A strong type of dipole-dipole interaction involving a hydrogen atom attached to O, N, or F and a lone pair on another O, N, or F atom.

Protic Solvent

A solvent that has a hydrogen atom attached to an electronegative atom (O or N) and can donate hydrogen bonds.

Aprotic Solvent

A solvent that does not have a hydrogen atom attached to an electronegative atom and cannot donate hydrogen bonds.