Chemistry Resonance and Conjugation Quiz

A type of chemical bonding where electrons are shared between atoms, but the electrons are not localized to a particular bond and can move freely over a larger region.

A molecule that can be represented by multiple Lewis structures that differ only in the placement of π electrons. These structures collectively represent the molecule's actual structure, a resonance hybrid.

A hybrid of two or more contributing resonance structures, representing the molecule's actual distribution of electrons.

A type of orbital hybridization where one s orbital and two p orbitals combine to form three sp² orbitals, resulting in a trigonal planar geometry.

A system of atoms with overlapping p orbitals, allowing for the delocalization of electrons over a larger region. This results in enhanced stability and unique properties.

A type of bond formed by the overlap of p orbitals, typically between adjacent sp² hybridized carbon atoms.

The ability of electrons in π bonds to move freely over a larger region of the molecule, due to conjugation.

An atom or group of atoms that donates electrons to an electron-deficient region, often through conjugation. It participates in resonance structures by shifting its electron density.

A type of isomer where molecules differ in the position of a hydrogen atom and easily convert into each other.

The process by which two tautomers interconvert, usually involving the movement of a hydrogen atom.

Electronegativity describes an atom's tendency to attract shared electrons in a bond. High electronegativity means a strong attraction for electrons.

Atoms with high electronegativity tend to form negative charges, while those with low electronegativity tend to form positive charges.

The chemical bond formed by the direct overlap of atomic orbitals, creating a single, concentrated area of electron density.

The chemical bond formed by the side-by-side overlap of atomic orbitals, resulting in a region of electron density above and below the bond axis.

A system where alternating double and single bonds allow electrons to move freely across the molecule.

A molecule that readily accepts electrons, often lacking electrons in its outer shell.

An sp3 hybridized carbon atom interrupts the delocalization of pi electrons within a conjugated system because it only forms localized sigma bonds.

Atoms with lone pairs of electrons, like oxygen and nitrogen, can participate in pi electron delocalization because they contribute their lone pairs to the conjugated system.

Resonance structures are different Lewis structures of a molecule that can be interconverted by moving electrons. They represent the delocalization of pi electrons within a conjugated system.

To identify potential resonance structures, look for sp2 hybridized carbons (those with a double bond), atoms with lone pairs (like O or N), and carbocations or carbanions. These are involved in pi delocalization.

In a Lewis structure, a conjugated pi system often corresponds to an alternating pattern of single and double bonds. This pattern allows for the delocalization of pi electrons.

The formal charge on an atom is calculated by comparing its valence electrons to the number of electrons it owns in the Lewis structure (lone pairs and half the bonding electrons).

The most stable resonance structures are those with the fewest formal charges and the negative charges on electronegative atoms.

Resonance structures significantly contribute to the stability of carbocations and carbanions by delocalizing the positive or negative charge over a larger region.

A rule that states that the electrophile (proton) in the addition of HX to an alkene will bind to the carbon with more hydrogen substituents, while the halide (X) will bind to the carbon with more alkyl substituents.

A positively charged carbon atom formed during the addition reaction of an alkene.

The more substituted a carbocation is, the more stable it is due to inductive and hyperconjugative effects.

The addition of HX to an alkene will create a carbocation intermediate. The more stable carbocation will be the major product, leading to the hydrogen being attached to the less substituted carbon and the halide to the more substituted carbon.

A type of reaction where a nucleophile attacks the carbonyl carbon of a carboxylic acid derivative, replacing the leaving group with the nucleophile.

A key difference between carboxylic acid derivatives and ketones/aldehydes is that the former can undergo nucleophilic acyl substitution reactions, while the latter undergo nucleophilic additions.

The atom adjacent to the carbonyl carbon in carboxylic acid derivatives is an electronegative heteroatom, which is crucial for understanding the reactivity of these molecules.

The 'acyl X group' in carboxylic acid derivatives acts as a potential leaving group, making it possible for nucleophilic acyl substitution to occur.

In a nucleophilic acyl substitution reaction, a nucleophile attacks the carbonyl carbon, forming a temporary, unstable intermediate called the tetrahedral intermediate.

A reaction in which a nucleophile replaces a leaving group attached to a carbonyl carbon, specifically in a molecule containing an acyl group.

In nucleophilic acyl substitution reactions, the carbonyl carbon in the acyl compound is attacked by the nucleophile, forming a tetrahedral intermediate. The tetrahedral intermediate is stabilized by hydrogen bonding interactions, particularly with the negatively charged oxygen atom, often facilitated by enzymatic residues in the active site.

The process of removing a carboxyl group (COOH) from a molecule, often during metabolic pathways. This process releases carbon dioxide and can generate energy or create new molecules.

The formation of a peptide bond, a key linkage in proteins, is a classic example of a nucleophilic acyl substitution reaction. The amino group of one amino acid attacks the carboxyl group of another, resulting in the peptide bond.

Enzymes like NAD+ and FAD are crucial for capturing electrons released during reactions like decarboxylation. They act as electron carriers, facilitating redox reactions within cells.

The process of adding oxygen atoms to a molecule, often increasing its oxidation state. In the context of the content provided, carbon oxidation can be considered a series of reactions leading to a molecule with increasing numbers of carbon-oxygen bonds.