Organic Chemistry: Chemical Bonding and Formal Charge Flashcards

Vocabulary flashcards covering ionic and covalent bonding, electronegativity limits, formal charge calculations, and molecular structures based on the lecture transcript.

Ionic Bond

A chemical bond characterized by complete (100%) electron transfer between atoms, forming positive and negative ions; typically occurs when the electronegativity difference is above $2.1$.

Covalent Bond

A chemical bond where electrons are shared between atoms rather than transferred; occurs when the electronegativity difference between atoms is lower than $1.9$.

Nonpolar Covalent Bond

A covalent bond where electrons are shared equally between two atoms, occurring when the electronegativity difference is below $0.5$ (e.g., a carbon-hydrogen bond with an electronegativity difference of $0.4$).

Polar Covalent Bond

A covalent bond where electrons are shared unequally between atoms due to an electronegativity difference (e.g., hydrogen fluoride with an electronegativity difference of $1.9$).

Formal Charge

A calculated value for an atom given by the formula: $\text{Formal Charge} = \text{number of valence electrons} - \frac{1}{2}(\text{bonding electrons}) - \text{nonbonding electrons}$.

Neutral Atom

An atom within a chemical structure that has a formal charge of $0$.

Ammonia

The compound $NH_3$, in which the central nitrogen atom forms three bonds, has one lone pair, and carries a formal charge of $0$.

Ammonium

The ion $NH_4^+$ in which nitrogen forms four bonds with no lone pairs, resulting in a formal charge of $+1$.

Carbocation

An unstable carbon species containing three single bonds, zero lone pairs, and a formal charge of $+1$ that does not satisfy the octet rule.

Carbanion

A carbon species containing three single bonds, one lone pair, and a formal charge of $-1$.

Molecular Polarity

A property of a molecule determined by the spatial arrangement of its atoms and its molecular geometry derived from VSEPR theory.