Calculations for Organic Chemistry I (Chem 230-02)

A collection of vocabulary flashcards derived from Organic Chemistry lecture notes focusing on key concepts, formulas, and definitions.

Degree of Unsaturation (DoU)

A mathematical expression used to determine the number of rings and multiple bonds present in a compound.

General Formula for Saturated Hydrocarbon

CnH2n+2, where n is the number of carbon atoms.

General Formula for Unsaturated Hydrocarbon

CnH2n, where n is the number of carbon atoms.

Units of Unsaturation

Refers to rings and multiple bonds in organic compounds; one unit for each bond or ring present.

Heat of Formation (ΔHfo)

The heat energy released or absorbed during the formation of a substance from its elements.

Strain Energy

The excess energy in cyclic compounds due to angle, torsional, and steric strain.

Cycloalkanes

Cyclic alkanes with the general formula CnH2n that can exhibit strain energy due to their ring structure.

Optical Purity

The measure of a sample's pureness in terms of its active enantiomers compared to a pure enantiomer.

Enantiomeric Excess (ee)

The difference in percentage between the amounts of two enantiomers present in a mixture.

Racemic Mixture

A mixture that contains equal amounts of both enantiomers, resulting in optical inactivity.

Specific Rotation

The observed rotation of polarized light by a chiral compound in solution, usually measured in degrees.

Strain Energy in Cyclohexane

Virtually strain-free as it adopts bond angles close to ideal and features staggered arrangements of C-H bonds.

ΔHfo per Methylene Group (CH2) in Cyclohexane

Calculated as -4.9 kcal/mol, representing the heat of formation for a strain-free methylene.

Calculation of Strain Energy for Cyclobutane

Involves comparing the actual ΔHfo with the hypothetical ΔHfo for an unstrained cycloalkane.

Strain Energy Equation

Strain energy equals the actual ΔHfo minus the hypothetical unstrained ΔHfo.

Percent Optical Purity Calculation

Calculated as (observed specific rotation of mixture)/(specific rotation of pure enantiomer) x 100.

Example of Specific Rotation Calculation

If the specific rotation of a mixture is -134 and of pure enantiomer is -158, use to find optical purity.

Aliphatic Straight-chain Alkenes

Hydrocarbons that follow specific formulas to calculate degrees of unsaturation without heteroatoms.