question

acyclic

answer

noncyclic

question

alkane

answer

A saturated hydrocarbon; a hydrocarbon that has no carbon - carbon multiple bonds; has only carbon-carbon single bonds; formerly called the paraffin series.

question

alkyl group

answer

the group of atoms remaining after a hydrogen atom is removed from an alkane: an alkane-like substituent . symbolized by R

question

amyl

answer

an older common name for pentyl

question

angle strain or baeyar strain

answer

the strain associated with distorting bond angles to smaller or larger angles

question

anti conformation

answer

the geometric arrangement around a carbon-caron single bond in which the two largest substituents are 180 degrees apart as viewed in a Newman projection

question

aromatic hydrocarbon

answer

a hydrocarbon having a benzene-like aromatic ring

question

axial bond

answer

one of the six bonds (three up and three down) on the chair conformation of the cyclohexane ring that are parallel to the "axis" of the ring The axil bonds are shown in red, and the equatorial bond is green

question

bridged bicyclic compound

answer

a compound containing two rings joined at nonadjacent carbon atoms

question

bridgehead carbons

answer

the carbon atoms shared by two or more rings. Three chains of carbon atoms (bridges) connect the bridgeheads

question

chair-chair interconversion

answer

(ring-flip) the process of one chair conformation of a cyclohexane flipping into one another , with all the axial and equatorial position reversed . the boat (or twist boat) conformation in an intermediate for the chair -chair interconversion

question

cis-trans isomers

answer

(geometric isomers) stereoisomers that differ only with respect to their cis or trans arrangement on a ring or double bond

question

cis:

answer

having two similar groups directed toward the same face of a ring or double bond

question

trans:

answer

having two similar groups directed towards opposite faces of a ring or double bond

question

combustion

answer

a rapid oxidation at high temperatures in the presence of air or oxygen

question

common names

answer

the names that have developed historically, generally with a specific name for each com compound: also called trivial names

question

conformational analysis

answer

the study of the energetics of different conformations

question

conformations and conformers

answer

structures that are related by rotations about a single bond. Strictly speaking, a conformer is a conformation that corresponds to a relative minimum energy usually a staggered conformation. In most cases , conformations and conformers interconvert at room temperature, and they are not true isomers

question

Know the conformations of cyclohexanes

answer

chair half chair boat twist boat

question

chair conformation

answer

conformation of cyclohexane with almost no angle strain resembles a chair, all neighboring C-H bonds are staggered - most stable

question

boat conformation

answer

the less stable puckered conformation of cyclohexane, with both parts puckered upward. The most stable boat is actually the twist boat ( or simple twist) conformation. Twisting minimizes torsional strain and steric strain

question

flag pole hydrogens

answer

two hydrogens (blue) in the boat conformation point upwards like flagpoles. the twist boat reduces the steric repulsion of the flagpole hydrogens

question

half-chair conformation

answer

the unstable conformation halfway between the chair conformation and the boat conformation .part of the ring is flat in the half-chair conformation.

question

constitutional isomers

answer

(structural isomers) Isomers who's atoms are connected differently: they differ in their bonding sequence.

question

cracking

answer

heating large alkanes to cleave them into smaller molecules

question

catalytic cracking

answer

cracking the presence of catalyst

question

hydrocracking

answer

catalyst cracking the the presences of hydrogen to give mixtures an alkanes

question

cyclic

answer

congaing of ring of atoms

question

cycloalkane

answer

an alkane containing a ring of carbon atoms: general formula : CnH2n

question

degree of alkyl substitution

answer

the number of alkyl groups bonded to a carbon atom in a compound or in an alkyl group

question

Primary degree

answer

``H ``| R--C--H ``| ``H

question

Secondary degree

answer

```H ```| R--C--H ``` | ```R

question

Tertiary Degree

answer

```H ```| R--C--R ```| ```R

question

Quaternary Degree

answer

```R ```| R--C--R ``| ``R

question

1,3 -diaxial interaction

answer

the strong steric strain between two axial groups on cyclohexane carbons with one carbon between them

question

dihedral angle

answer

the angle between two specified groups in a newman project

question

eclipsed conformation

answer

any conformation with bonds directly lined up with each other , one behind the other, in the Newman project. The conformation with 0= zero degrees in an eclipsed conformation.

question

equatorial bond

answer

on of the six bonds (three up three down) on the cyclohexane ring that are directed out toward the "equator" of the ring. The equatorial bonds are shown in green in the drawing in the drawing at right

question

fused ring system

answer

a molecule in which two or more rings share two adjacent carbon atoms

question

gauche conformation

answer

a conformation with a 60 degree dihedral angle between the largest groups

question

geometric isomers

answer

Compounds that have the same covalent partnershipds, but differ in spatial arrangements

question

halogenation

answer

the reaction of alkanes with halogens, in the presence of heat or light, to give products with halogens atoms substituted for hydrogen atoms

question

Formula for halogenation

answer

R-H+X2 when added heat or light transforms to R-X+XH x= F, Cl, Br

question

heat of combustion

answer

the heat given off when a mole of a compound is burned with excess oxygen to give CO2 and H20 in a bomb calorimeter. A measure of the energy content of a molecule.

question

homologs

answer

two compounds that differ only by one or more -CH2- groups

question

hydrophilic

answer

attracted to water: soluble in water

question

hydrophobic

answer

repelled by water : insoluble in water

question

IUPAC Names

answer

the systematic names that follow the rules adopted by the International Union Of Pure and Applies Chemistry

question

kerosene

answer

A thin, volatile oil distilled from petroleum, with a boiling range higher than that of gasoline and lower than that of diesel fuel. Kerosene was once used in lanterns and heaters, but now most of this petroleum fraction is further refined for use as jet fuel

question

methane hydrate

answer

An ice-like substance consisting of individual methane molecules trapped inside cages of water molecules.

question

methine group

answer

The- CH-group.

question

methylene group

answer

The -CH2- group.

question

methyl group

answer

The -CH3- group.

question

n-alkane, normal alkane, or straight-chain alkane

answer

An alkane with all its carbon atoms in a single chain, with no branching or alkyl substituents.

question

Newman projections

answer

a way of drawing the conformations of a molecule by looking straight down the bond connecting two carbon atoms

question

octane number

answer

A rating of the antiknock properties of a gasoline blend. Its octane number is the percentage of isooctane (2,2,4-trimethylpentane) in an isooctane/heptane blend that begins to knock at the same compression ratio as the gasoline being tested.

question

paraffins

answer

Another term for alkanes.

question

ring strain

answer

The extra strain associated with the cyclic structure of a compound, as compared with a similar acyclic compound; composed of angle strain and torsional strain.

question

angle strain or Baeyer strain:

answer

The strain associated with distorting bond angles to smaller (or larger) angles

question

torsional strain:

answer

The strain associated with eclipsing of bonds in the ring.

question

saturated

answer

Having no double or triple bonds.

question

sawhorse structures

answer

A way of picturing conformations by looking down at an angle toward the carbon-carbon bond

question

skew conformation

answer

Any conformation that is not precisely staggered or eclipsed.

question

spirocyclic compounds

answer

Bicyclic compounds in which the two rings share only one carbon atom.

question

staggered conformation

answer

Any conformation with the bonds equally spaced in the Newman projection. The conformation with 0= 60 degrees is a staggered conformation.

question

steric strain

answer

The interference between two bulky groups that are so close together that their electron clouds experience a repulsion

question

substituent

answer

A side chain or appendage on the main chain.

question

systematic names

answer

Same as IUPAC names, the names that follow the rules adopted by the International Union of Pure and Applied Chemistry. (

question

torsional energy or conformational energy

answer

The energy required to twist a bond into a specific conformation.

question

torsional strain

answer

The resistance to twisting about a bond.

question

totally eclipsed conformation

answer

A conformation with a 0 dihedral angle between the largest groups. Usually the highest-energy conformation

question

Using the general molecular formula for alkanes: (a) Predict the molecular formula of the straight-chain alkane

answer

...

question

) Predict the molecular formula of 4,6-diethyl-12-(3,5-dimethyloctyl)triacontane, an alkane containing 44 carbon atoms.

answer

...

question

Write structures for the following compounds

answer

(a) 3-ethyl-4-methylhexane (b) 3-ethyl-5-isobutyl-3-methylnonane (c) 4-tert-butyl-2-methylheptane (d) 5-isopropyl-3,3,4-trimethyloctane

question

Provide IUPAC names for compounds.

answer

...

question

All of the following names are incorrect or incomplete. In each case, draw the structure (or a possible structure) and name it correctly

answer

(a) 2-methylethylpentane (b) 2-ethyl-3-methylpentane (c) 3-dimethylhexane (d) 4-isobutylheptane (e) 2-bromo-3-ethylbutane (f) 2-diethyl-3-methylhexane

question

Give structures and names for:

answer

a) the five isomers of C6H14 (b) the nine isomers of C7H16

question

Draw the structures of the following groups, and give their more common names.

answer

(a) the (1-methylethyl) group (b) the (2-methylpropyl) group (c) the (1-methylpropyl) group (d) the (1,1-dimethylethyl) group (e) the (3-methylbutyl) group, sometimes called the "isoamyl" group

question

Draw the structures of the following compounds.

answer

(a) 4-(1,1-dimethylethyl)octane (b) 5-(1,2,2-trimethylpropyl)nonane (c) 3,3-diethyl-4-(2,2-dimethylpropyl)octane

question

Without looking at the structures, give molecular formulas for the compounds Use the names of the groups to determine the number of carbon atoms, then use the 12n+22 rule.

answer

(a) 4-(1,1-dimethylethyl)octane (b) 5-(1,2,2-trimethylpropyl)nonane

question

List each set of compounds in order of increasing boiling point. hexane, octane, and decane

answer

...

question

List each set of compounds in order of increasing boiling point. octane, and (CH3) 3C-C(CH3)3C and CH3CH2C(CH3)2CH2CH2CH3

answer

...

question

Draw a graph, similar to Figure 3-9, of the torsional strain of 2-methylpropane as it rotates about the bond between C1 and C2. Show the dihedral angle and draw a Newman projection for each staggered and eclipsed conformation.

answer

...

question

Draw a graph, similar to Figure 3-11, of the torsional energy of 2-methylbutane as it rotates about the bond.

answer

...

question

Draw a perspective representation of the most stable conformation of 3-methylhexane

answer

...

question

Draw the structure and give the molecular formula for each of the following compounds.

answer

(a) 1-ethyl-3-methylcycloheptane (b) isobutylcyclohexane (c) cyclopropylcyclopentane (d) 3-ethyl-1,1-dimethylcyclohexane (e) 3-ethyl-2,4-dimethylhexane (f) 1,1-diethyl-4-(3,3-dimethylbutyl)cyclohexane

question

Which of the following cycloalkanes are capable of geometric (cis-trans) isomerism? Draw the cis and trans isomers.

answer

(a) 3-ethyl-1,1-dimethylcyclohexane (b) 1-ethyl-3-methylcycloheptane (c) 1-ethyl-3-methylcyclopentane (d) 1-cyclopropyl-2-methylcyclohexane

question

The heat of combustion of cis-1,2-dimethylcyclopropane is larger than that of the trans isomer. Which isomer is more stable? Use drawings to explain this difference in stability.

answer

...

question

trans-1,2-Dimethylcyclobutane is more stable than cis-1,2-dimethylcyclobutane, but cis-1,3- dimethylcyclobutane is more stable than trans-1,3-dimethylcyclobutane. Use drawings to explain these observations.

answer

...

question

The cyclohexane chair just drawn has the headrest to the left and the footrest to the right. Draw a cyclohexane chair with its axial and equatorial bonds, having the headrest to the right and the footrest to the left.

answer

...

question

Draw 1,2,3,4,5,6-hexamethylcyclohexane with all the methyl groups (a) in axial positions. (b) in equatorial positions

answer

...

question

Draw a Newman projection, similar to Figure 3-25, down the bond in the equatorial conformation of methylcyclohexane. Show that the equatorial methyl group is also anti to C5. (Using your models will help.)

answer

...

question

Draw a Newman projection, similar to Figure 3-25, down the bond in the equatorial conformation of methylcyclohexane. Show that the equatorial methyl group is also anti to C5. (Using your models will help.)

answer

...

question

Draw the most stable conformation of: (a) ethylcyclohexane (b) 3-isopropyl-1,1-dimethylcyclohexane (c) cis-1-tert-butyl-4-isopropylcyclohexane

answer

...

question

(a) Draw both chair conformations of cis-1,2-dimethylcyclohexane, and determine which conformer is more stable. (b) Repeat for the trans isomer. (c) Predict which isomer (cis or trans) is more stable.

answer

...

question

(a) Draw both chair conformations of cis-1,4-dimethylcyclohexane, and determine which conformer is more stable. (b) Repeat for the trans isomer. (c) Predict which isomer (cis or trans) is more stable.

answer

...

question

Use your results from Problem 3-25 to complete the following table. Each entry shows the positions of two groups arranged as shown. For example, two groups that are trans on adjacent carbons (trans-1,2) must be both equatorial (e,e) or both axial (a,a).

answer

...

question

Draw the most stable conformation of trans-1-ethyl-3-methylcyclohexane.

answer

...

question

Draw the two chair conformations of each of the following substituted cyclohexanes. In each case, label the more stable conformation

answer

(a) cis-1-ethyl-2-methylcyclohexane (b) trans-1,2-diethylcyclohexane (c) cis-1-ethyl-4-isopropylcyclohexane (d) trans-1-ethyl-4-methylcyclohexane

question

Name the following compounds. Remember that two up bonds are cis; two down bonds are cis; one up bond and one down bond are trans.

answer

...

question

Draw the most stable conformation of

answer

(a) cis-1-tert-butyl-3-ethylcyclohexane (b) trans-1-tert-butyl-2-methylcyclohexane (c) trans-1-tert-butyl-3-(1,1-dimethylpropyl)cyclohexane

question

Given the IUPAC name or common name of an alkane, draw the structure and give the molecular formula

answer

...

question

Explain and predict trends in the physical properties of alkanes.

answer

...

question

Use Newman projections to compare conformational energies and predict the most stable conformation. Show how the torsional energy varies as the dihedral angle changes

answer

...

question

Use Newman projections to compare conformational energies and predict the most stable conformation. Show how the torsional energy varies as the dihedral angle changes

answer

...

question

Identify and draw cis and trans stereoisomers of disubstituted cycloalkanes.

answer

...

question

Identify and draw cis and trans stereoisomers of disubstituted cycloalkanes.

answer

...

question

There are eighteen isomeric alkanes of molecular formula C8H18. Draw and name any eight of them

answer

...

question

Draw and name the six isomeric cyclopentanes of molecular formula . These will include four constitutional isomers, of which two show geometric (cis-trans) stereoisomerism

answer

...

question

Which of the following structures represent the same compound? Which ones represent different compounds?

answer

...

question

Name the structures given in Problem 3-33, parts (a), (c), (e), and (f). Make sure that your names are the same for structures that are the same, and different for structures that are different.

answer

...

question

Draw the structure that corresponds with each name.

answer

(a) 3-ethyloctane (b) 4-isopropyldecane (c) sec-butylcycloheptane (d) 2,3-dimethyl-4-propylnonane (e) 2,2,4,4-tetramethylhexane (f) trans-1,3-diethylcyclopentane (g) cis-1-ethyl-4-methylcyclohexane (h) isobutylcyclopentane (i) tert-butylcyclohexane (j) pentylcyclohexane (k) cyclobutylcyclohexane (l) cis-1-bromo-3-chlorocyclohexane

question

Each of the following descriptions applies to more than one alkane. In each case, draw and name two structures that match the description.

answer

(a) an isopropylheptane (b) a diethyldecane (c) a cis-diethylcyclohexane (d) a trans-dihalocyclopentane (e) a (2,3-dimethylpentyl)cycloalkane (f) a bicyclononane

question

Write structures for a homologous series of alcohols having from one to six carbons.

answer

...

question

The following names are all incorrect or incomplete, but they represent real structures. Draw each structure and name it correctly.

answer

(a) 2-ethylpentane (b) 3-isopropylhexane (c) 5-chloro-4-methylhexane (d) 2-dimethylbutane (e) 2-cyclohexylbutane (f) 2,3-diethylcyclopentane

question

In each pair of compounds, which compound has the higher boiling point? Explain your reasoning

answer

(a) octane or 2,2,3-trimethylpentane (b) nonane or 2-methylheptane (c) 2,2,5-trimethylhexane or nonane

question

There are eight different five-carbon alkyl groups

answer

(a) Draw them. (b) Give them systematic names. (c) In each case, label the degree of substitution (primary, secondary, or tertiary) of the head carbon atom, bonded to the main chain.

question

Use a Newman projection, about the indicated bond, to draw the most stable conformer for each compound.

answer

(a) 3-methylpentane about the bond b) 3,3-dimethylhexane about the bond

question

Draw the two chair conformations of cis-1,3-dimethylcyclohexane and label all the positions as axial or equatorial (b) Label the higher-energy conformation and the lower-energy conformation. (c) The energy difference in these two conformations has been measured to be about 23 kJ (5.4 kcal) per mole. How much of this energy difference is due to the torsional energy of gauche relationships? (d) How much energy is due to the additional steric strain of the 1,3-diaxial interaction?

answer

...

question

raw the two chair conformations of each compound and label the substituents as axial and equatorial. In each case, determine which conformation is more stable

answer

(a) cis-1-ethyl-2-isopropylcyclohexane (b) trans-1-ethyl-2-isopropylcyclohexane (c) cis-1-ethyl-3-methylcyclohexane (d) trans-1-ethyl-3-methylcyclohexane (e) cis-1-ethyl-4-methylcyclohexane (f) trans-1-ethyl-4-methylcyclohexane

question

using what you know about the informational energies of substituted cyclohexanes, predit which of th two decal in isomers is more stable. Explain your reason

answer

...

question

Convert each Newman projection to the equivalent line-angle formula, and assign the IUPAC name.

answer

...

question

Draw Newman projections along the bond to show the most stable and least stable conformations of 3-ethyl- 2,4,4-trimethylheptane

answer

...

question

Conformational studies on ethane-1,2-diol ( ) have shown the most stable conformation about the central c-c bond to be the gauche conformation, which is 9.6 kJ/mol (2.3 kcal/mol) more stable than the anti conformation. Draw Newman projections of these conformers and explain this curious result.

answer

...

question

The most stable form of the common sugar glucose contains a six-membered ring in the chair conformation with all the substituents equatorial. Draw this most stable conformation of glucose.

answer

...

question

Determine whether the following objects are chiral or achiral.

answer

roll of duck tape can opener snow sled wind bottle cork screw wooden student chain salt shaker metal spoon rifle knotted rope

question

Make a model and draw a three dimensional structure for each compound. Then draw the mirror image of your original structure and determine whether the mirror image is the same compound. Label each structure as being chiral or archiral and label of enantiomers

answer

(a) cis-1,2-dimethylcyclobutane (b) trans-1,2-dimethylcyclobutane (c) cis- and trans-1,3-dimethylcyclobutane (d) 2-bromobutane

question

Identify each asymmetric carbon atom in the following structure:

answer

...

question

Identify each asymmetric carbon atom in the following structure:

answer

...

question

Draw the enantiomers of 1,3-dibromobutane and label them as (R) and (S). (Making a model is particularly helpful for this type of problem.

answer

...

question

When one of the enantiomers of butan-2-ol is placed in a polarimeter, the observed rotation is 4.05° counterclockwise. The solution was made by diluting 6.00 g of butan-2-ol to a total of 40.0 mL, and the solution was placed into a 200-mm polarimeter tube for the measurement. Determine the specific rotation for this enantiomer of butan-2-ol.

answer

Since it is levorotatory, this must be The concentration is 6.00 g per and the path length is The specific rotation is -13.5°. [a]D 25 = -4.05° 10.150212.002 = -13.5° 40.0 mL = 0.150 g>mL, 200 mm = 2

question

A solution of 2.0 g of in 10.0 mL of water was placed in a 100-mm cell. Using the sodium D line, a rotation of was found at 25 °C. Determine the specific rotation of 1+2-glyceraldehyde.

answer

...

question

A chiral sample pair give a rotation the is close to 180 degrees. How can one tell the weather this rotation is + 180 degrees or - 180 degrees

answer

...

question

If you had the two enantiomers of carvone in unmarked bottles, could you use just your nose and a polarimeter to determine:

answer

(a) whether it is the or enantiomer that smells like spearmint? (b) whether it is the (R) or (S) enantiomer that smells like spearmint? (c) With the information given in the drawings of carvone above, what can you add to your answers to (a) or (b)?

question

Calculate the e.e. and the specific rotation of a mixture containing 6.0 g of and 4.0 g of (-) - butan-2ol

answer

SOLUTION In this mixture, there is a 2.0 g excess of the isomer and a total of 10.0 g, for an e.e. of 20%. We can envision this mixture as 80% racemic [4.0 g and 4.0 g ] and 20% pure The specific rotation of enantiomerically pure is . The rotation of this mixture is = 1+13.5°2 * 120%2 = +2.7° observed rotation = 1rotation of pure enantiomer2 * 1o.p.2 1+2-butan-2-ol +13.5° o.p. = e.e. = ƒ6.0 - 4.0ƒ 6.0 + 4.0 = 2.0 10.0 = 20% (+) (-) (+). (+) 1-2-butan-2-ol. 1+2-butan-2-ol

question

A chemist finds that the addition of to the catalytic reduction of butan-2-one (Figure 5-16) gives a product that is slightly optically active, with a specific rotation of Calculate the percentages of and formed in this reaction. 1+2-butan-2-ol 1-2-butan-2-ol +0.45°.

answer

...

question

Draw each compound in its most stable conformation(s). Then draw it in its most symmetric conformation, and determine whether it is capable of showing optical activity. (a) 2-methylbutane (b) trans-1,2-dibromocyclohexane

answer

...

question

Make a model of each compound, draw it in its most symmetric conformation, and determine whether it is capable of showing optical activity

answer

(a) 1-bromo-1-chloroethane (b) 1-bromo-2-chloroethane (c) 1,2-dichloropropane (d) cis-1,3-dibromocyclohexane (e) trans-1,3-dibromocyclohexane (f) trans-1,4-dibromocyclohexane

question

Star each asymmetric carbon atom, label each as (R) or (S), and compare your result from part (1) with the prediction you would make based on the asymmetric carbons.

answer

...

question

Draw all the stereoisomers of a given structure, and identify the relationships between the stereoisomers.

answer

...

question

Classify molecules as chiral or achiral, and draw their mirror images. Identify and draw any mirror planes of symmetry

answer

...

question

Identify asymmetric carbon atoms, and name them using the (R) and (S) nomenclature.

answer

...

question

Calculate specific rotations from polarimetry data, and use specific rotations to determine the optical purity and the enantiomeric excess of mixtures.

answer

...

question

Use Fischer projections to represent the stereochemistry of compounds with one or more asymmetric carbon atoms.

answer

...

question

Identify pairs of enantiomers, diastereomers, and meso compounds, and explain how they differ in their physical and chemical properties.

answer

...

question

Explain how different types of stereoisomers can be separated.

answer

...

question

absolute configuration

answer

The detailed stereochemical picture of a molecule, including how the atoms are arranged in space. Alternatively, the (R) or (S) configuration at each asymmetric carbon atom.

question

achiral

answer

achiral Not chiral.

question

allenes

answer

Compounds having two double bonds that meet at a single carbon atom, C=C=C The two outer carbon atoms are trigonal planar, with their planes perpendicular to each other. Many substituted allenes are chiral.

question

asymmetric carbon atom

answer

(chiral carbon atom) A carbon atom that is bonded to four different groups

question

Cahn-Ingold-Prelog convention

answer

The accepted method for designating the absolute configuration of a chirality center (usually an asymmetric carbon) as either (R) or (S).

question

chiral

answer

Different from its mirror image.

question

chiral carbon atom

answer

asymmetric carbon atom) A carbon atom that is bonded to four different groups.

question

chirality center

answer

the IUPAC term for an atom holding a set of ligands in a spatial arrangement that is not superimposable on its mirror image

question

chiral probe

answer

A molecule or an object that is chiral and can use its own chirality to differentiate between mirror images. (

question

cis

answer

On the same side of a ring or double bond.

question

cis-trans isomers

answer

(geometric isomers) Isomers that differ in their geometric arrangement on a ring or double bond; cis-trans isomers are a subclass of diastereomers

question

configurations

answer

The two possible spatial arrangements around a chirality center or other stereocenter.

question

configurational isomers

answer

(see stereoisomers)

question

conformers

answer

(conformational isomers) Structures that differ only by rotations about single bonds. In most cases, conformers interconvert at room temperature; thus, they are not different compounds and not true isomers

question

constitutional isomers

answer

(structural isomers) Isomers that differ in the order in which their atoms are bonded together.

question

D-L configurations

answer

(Fischer- Rosanoff convention) D has the same relative configuration at (=) - glyceraldehyde. L as the same relative configuration as (-)

question

dextrorotatory, or (d)

answer

Rotating the plane of polarized light clockwise.

question

dextrorotatory, (+) or (d)

answer

Rotating the plane of polarized light clockwise.

question

diastereomers

answer

Stereoisomers that are not mirror images.

question

enantiomeric excess (e.e.)

answer

The excess of lone enatiomer in a mixture of enantiomer expressed as a percentage of the mixture. Similar to optical purity

question

enantiomers

answer

A pair of nonsuperimposable mirror-image molecules: mirror-image isomers.

question

Fischer projection

answer

A method for drawing an asymmetric carbon atom as a cross. The carbon chain is kept along the vertical, with the IUPAC numbering from top to bottom. Vertical bonds project away from the viewer, and horizontal bonds project toward the viewer.

question

geometric isomers

answer

(see cis-trans isomers)

question

internal mirror plane

answer

A plane of symmetry through the middle of a molecule, dividing the molecule into two mirror-image halves. A molecule with an internal mirror plane of symmetry cannot be chiral

question

isomers

answer

Different compounds with the same molecular formula.

question

Leftorium

answer

An imaginary store that sells the enantiomers of everyday chiral objects such as scissors, rifles, can openers, etc

question

levorotatory, or (l)

answer

Rotating the plane of polarized light counterclockwise.

question

meso compound

answer

An achiral compound that contains chirality centers (usually asymmetric carbon atoms). Originally, an achiral compound that has chiral diastereomers.

question

optical isomers

answer

(archaic; see enantiomers) Compounds with identical properties except for the direction in which they rotate polarized light.

question

optical activity

answer

Rotation of the plane of polarized light.

question

optically active

answer

Capable of rotating the plane of polarized light

question

optical purity (o.p.)

answer

the specific rotation of a mixture of two enantiomers, expressed as a percentage of the specific rotation of one of the pure enantiomers. similar to enantiomeric excess.

question

plane-polarized light

answer

Light composed of waves that vibrate in only one plane.

question

polarimeter

answer

An instrument that measures the rotation of plane-polarized light by an optically active compound. (

question

racemic mixture

answer

a mixture of equal quants of enantiomers , such that the mixtures is optically inactive

question

relative configuration

answer

The experimentally determined relationship between the configurations of two molecules, even though the absolute configuration of either may not be known.

question

resolution

answer

stereocenter

question

resolving agent

answer

A chiral compound (or chiral material on a chromatographic column) used for separating enantiomers.

question

2 " rule

answer

A molecule with n chiral carbon atoms might have as many as stereoisomers.

question

specific rotation

answer

A measure of a compound's ability to rotate the plane of polarized light, given bywhere c is concentration in g mL and l is length of sample cell (path length) in decimeters

question

stereocenter

answer

(stereogenic atom) An atom that gives rise to stereoisomers when its groups are interchanged. Asymmetric carbon atoms and double-bonded carbons in cis-trans alkenes are the most common stereocenters.

question

stereochemistry

answer

The study of the three-dimensional structure of molecules

question

stereoisomers

answer

The study of the three-dimensional structure of molecules

question

structural isomers

answer

(see constitutional isomers) Isomers that differ in the order in which their atoms are bonded together.

question

superimposable

answer

(see constitutional isomers) Isomers that differ in the order in which their atoms are bonded together.

question

trans

answer

On opposite sides of a ring or double bond.

Organic Chem Ch 3 and 5 – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards