Test 2 Materials Flashcards
End of Chapter 3, Chapter 4 and Chapter 5
isopropyl
a 2 carbon branch plus a methyl
isobutyl
a 3 carbon branch plus a methyl on the second carbon
isopentyl
a 4 carbon branch plus a methyl
sec-butyl
a 3 carbon branch plus a methyl on the first carbon
neopentyl
a 3 carbon branch with 2 methyl groups on the 2nd carbon
tert-pentyl
a 3 carbon branch with 2 methyl groups on the 1st carbon
Alkanes are relatively ___ (reactive or inert). They do react with ___, and ___ under ultraviolet light.
Inert; Oxygen; Halides
Alkanes with higher molecular weights have ___ boiling points.
Higher
Alkanes with equal molecular weights but more branching have ___ boiling points due to dispersion forces.
Lower
Different arrangements of atoms due to bond rotation are called:
conformations
A dihedral angle
The angle between two intersecting planes (planes created by two sets of three atoms).
Which conformation is more stable, staggered or eclipsed?
Staggered. The dihedral angles are greater.
Electron repulsion between eclipsed bonds.
torsional strain
Repulsion interaction when atoms are forced closer together than atomic radii allows
steric hindrance
a staggered conformation with two high energy substituents next to each other.
Gauche
a staggered conformation with two high energy substituents opposing each other.
Anti
general formula of a cycloalkane
CnH2n
These isomers have atoms connected in the same order but different 3D orientation.
stereoisomers
Strain caused by bond angles forced to deviate from ideal 109 degrees.
angle strain
Larger substituents experience greater steric hindrance and are happier in the ___ position.
equatorial
the consequence of the tetrahedral stereochemistry of sp3-hybridized C atoms. Sp3 hybridized C atoms with 4 unique substituents have this quality.
handedness
non-superimposable mirror images which come in pairs
Enantiomers
a molecule that is superimposable on it’s mirror image is
achiral
a molecule that is not identical to its mirror image is said to be
chiral
if a molecule has a plane of symmetry it is
achiral
an enantiomer which rotates light counter clockwise is labeled negative and is called
levorotatory
an enantiomer which rotates light clockwise is labeled positive and is called
dextrorotatory
the extent to which an enantiomer rotates light is dependent on
the # of optically active molecules in the sample
when ranking atoms to determine configuration, atoms are ranked by their __
atomic number
R configuration
a clockwise path from atom 1 to 3 around the chiral center
s configuration
a counter clockwise path from atom 1 to 3 around the chiral center
Optical rotation sign (is/is not) related to R/S configuration.
IS NOT
This stereoisomer is oppositely configured at every chiral center.
Enantiomers
This stereoisomer is identical except for 1 chiral center
epimer
this stereoisomer is oppositely configured at some chiral centers
diastereomer
a molecule which contains chiral centers but do have a plane of symmetry. These molecules do not rotate polarized light.
meso compound
a 50:50 mixture of enantiomers
racemic mixture, a racemate
