Chemistry Test 2 Review: Organic Structures, Functional Groups, Thermodynamics, and Reactions

Vocabulary practice flashcards covering organic representations, functional group definitions, nomenclature, stereochemistry, thermodynamics, reaction mechanisms, and redox classifications from Test 2 Review.

Molecular formula

A chemical formula that only displays the total number of each atom present in a molecule without showing connectivity or bonds.

Condensed structural formula

A formula that includes each atom but shows as few bonds as possible, typically omitting lone pairs.

Lewis structure

A molecular representation that displays the complete connectivity of all atoms, covalent bonds, and lone pairs within a molecule.

Skeletal structure (line-bond structure)

A simplified molecular drawing showing carbon bonds as lines where vertices represent carbons and hydrogens bonded to carbon are implied, while heteroatoms are explicitly drawn.

Heteroatom

Any atom in an organic compound that is not carbon or hydrogen.

Functional group

A specific group of atoms bonded in a particular arrangement that confers characteristic physical properties and chemical reactivity to an organic molecule.

Alkane

A hydrocarbon containing exclusively carbon-carbon single bonds.

Alkene

A hydrocarbon containing one or more carbon-carbon double bonds.

Alkyne

A hydrocarbon containing one or more carbon-carbon triple bonds, representing the most reactive hydrocarbon class.

Aromatic hydrocarbon

A cyclic hydrocarbon containing alternating double bonds within a ring system.

Alcohol

A compound containing a hydroxyl group ($-\text{OH}$) bonded to a tetrahedral carbon atom, classified as primary ($1^\circ$), secondary ($2^\circ$), or tertiary ($3^\circ$ based on the number of carbons attached to the carbon bearing the hydroxyl group.

Phenol

An organic compound containing a hydroxyl group ($-\text{OH}$) bonded directly to an aromatic carbon atom.

Ether

A compound containing an oxygen atom connected by single bonds to two carbon groups that are either alkyl or aromatic groups.

Thiol

A sulfur-containing organic compound possessing a sulfhydryl group ($-\text{SH}$).

Sulfide (thioether)

A sulfur-containing compound in which a sulfur atom is bonded between two carbon groups ($\text{R}-\text{S}-\text{R}$).

Disulfide

A compound containing a covalent linkage between two sulfur atoms bonded to carbon groups ($\text{R}-\text{S}-\text{S}-\text{R}$).

Phosphate group

A functional group containing a central phosphorus atom bonded to four oxygen atoms, essential for cellular energy transfer, metabolic pathways, and nucleic acids.

Amine

A nitrogen-containing organic compound with alkyl groups or hydrogen atoms bonded to nitrogen, classified as primary ($1^\circ$), secondary ($2^\circ$), tertiary ($3^\circ$), or quaternary ($4^\circ$).

Carbonyl group

A functional group consisting of a carbon atom double-bonded to an oxygen atom ($\text{C}=\text{O}$).

Aldehyde

A carbonyl compound in which the carbonyl carbon is on a primary carbon bonded to at least one hydrogen atom.

Ketone

A carbonyl compound in which the carbonyl carbon is on a secondary carbon bonded to two carbon groups.

Carboxyl group

A functional group containing a carbonyl group directly bonded to a hydroxyl group ($-\text{COOH}$).

Carboxylate

The negatively charged, deprotonated form of a carboxylic acid ($-\text{COO}^-$), commonly present in amino acids at physiological conditions.

Ester

A carboxylic acid derivative containing a carbonyl group bonded to an oxygen that is attached to another carbon group ($\text{R}-\text{COO}-\text{R}'$).

Amide

A carboxylic acid derivative where a nitrogen-containing group replaces the hydroxyl ($-\text{OH}$) group of the carboxylic acid.

Saturated fatty acid

A lipid molecule consisting of a long, unbranched alkane-like hydrocarbon chain containing no carbon-carbon double bonds, ending with a carboxylic acid group.

Haloalkane (alkyl halide)

An alkane derivative containing one or more halogen atoms (fluoro, chloro, bromo, or iodo) acting as substituents.

Cycloalkane

A ring-forming saturated hydrocarbon where the ring acts as the parent chain and carbon 1 is designated at the site of substituent attachment.

Structural isomers

Compounds that share the identical molecular formula but possess different structural connectivity of their constituent atoms.

Conformational isomers

Molecules that have the same molecular formula and connectivity but differ temporarily due to rotation around single covalent bonds.

Cis-trans stereoisomers

Isomeric compounds that share the same atom connectivity but differ in the spatial orientation of groups across a rigid carbon-carbon double bond that restricts rotation.

Chiral molecule

A molecule that lacks an internal plane of symmetry and is not superimposable on its mirror image.

Change in enthalpy ($\Delta H$)

The thermodynamic heat exchange of a chemical reaction occurring at constant pressure, calculated as $\Delta H_{\text{reaction}} = \Delta H_{\text{products}} - \Delta H_{\text{reactants}}$.

Exothermic reaction

A chemical process that releases heat energy to the surroundings, yielding products with lower energy than reactants and a negative enthalpy change ($\Delta H < 0$).

Endothermic reaction

A chemical process that absorbs heat energy from the surroundings, yielding products with higher energy than reactants and a positive enthalpy change ($\Delta H > 0$).

Entropy ($\Delta S$)

A thermodynamic measure of disorder or molecular randomness in a system, determined by $\Delta S = \Delta S_{\text{products}} - \Delta S_{\text{reactants}}$.

Exergonic reaction

A spontaneous chemical process that releases free energy, characterized by a negative change in Gibbs free energy ($-\Delta G$), where $G_{\text{products}} < G_{\text{reactants}}$.

Activation energy ($E_a$)

The minimum threshold of kinetic energy required by colliding reactant molecules to break existing chemical bonds and initiate a reaction.

Synthesis reaction

A chemical transformation in which two or more reactants combine directly to produce a single product, modeled by $A + B \rightarrow AB$.

Decomposition reaction

A chemical transformation where a single compound breaks apart into two or more simpler chemical species, represented as $AB \rightarrow A + B$.

Exchange (displacement) reaction

A reaction where elements swap bonding partners, occurring as single exchange ($AB + C \rightarrow AC + B$) or double exchange ($AB + CD \rightarrow AD + CB$).

Combustion reaction

A reaction in which an organic compound reacts rapidly with oxygen gas ($O_2$) to generate carbon dioxide ($CO_2$), water ($H_2O$), and released energy.

Oxidation (inorganic)

The process in which an atom or ion loses electrons (OiL), typically resulting in a metal yielding a positive oxidation state.

Reduction (inorganic)

The process in which an atom or ion gains electrons (RiG), typically resulting in a nonmetal forming a negative charge.

Oxidizing agent

A reactant that facilitates oxidation by accepting electrons from another species, undergoing reduction in the process.

Organic redox reactions

Redox transformations in organic chemistry where oxidation corresponds to gaining oxygen or losing hydrogen, and reduction corresponds to gaining hydrogen or losing oxygen.

Condensation reaction (dehydration)

A chemical reaction in which two molecules combine covalently into a single larger molecule accompanied by the loss of a water molecule ($H_2O$).

Hydrolysis reaction

A chemical reaction where water ($H_2O$) is consumed as a reactant to split a larger molecule into two smaller molecules, such as the cleavage of ATP into ADP.

Hydration addition reaction

An electrophilic addition process where elements of water ($-\text{H}$ and $-\text{OH}$) are added across a carbon-carbon double bond in the presence of an acid or enzyme catalyst to form an alcohol.

Markovnikov's rule

A regiochemical rule stating that during the acid-catalyzed hydration of an asymmetric alkene, the hydroxyl group ($-\text{OH}$) preferentially attaches to the double-bond carbon with more carbon substituents (fewer hydrogens).