Test 2 Materials

Question 1

isopropyl

Answer 1

a 2 carbon branch plus a methyl

Question 2

isobutyl

Answer 2

a 3 carbon branch plus a methyl on the second carbon

Question 3

isopentyl

Answer 3

a 4 carbon branch plus a methyl

Question 4

sec-butyl

Answer 4

a 3 carbon branch plus a methyl on the first carbon

Question 5

neopentyl

Answer 5

a 3 carbon branch with 2 methyl groups on the 2nd carbon

Question 6

tert-pentyl

Answer 6

a 3 carbon branch with 2 methyl groups on the 1st carbon

Question 7

Alkanes are relatively ___ (reactive or inert). They do react with ___, and ___ under ultraviolet light.

Answer 7

Inert; Oxygen; Halides

Question 8

Alkanes with higher molecular weights have ___ boiling points.

Answer 8

Higher

Question 9

Alkanes with equal molecular weights but more branching have ___ boiling points due to dispersion forces.

Answer 9

Lower

Question 10

Different arrangements of atoms due to bond rotation are called:

Answer 10

conformations

Question 11

A dihedral angle

Answer 11

The angle between two intersecting planes (planes created by two sets of three atoms).

Question 12

Which conformation is more stable, staggered or eclipsed?

Answer 12

Staggered. The dihedral angles are greater.

Question 13

Electron repulsion between eclipsed bonds.

Answer 13

torsional strain

Question 14

Repulsion interaction when atoms are forced closer together than atomic radii allows

Answer 14

steric hindrance

Question 15

a staggered conformation with two high energy substituents next to each other.

Answer 15

Gauche

Question 16

a staggered conformation with two high energy substituents opposing each other.

Answer 16

Anti

Question 17

general formula of a cycloalkane

Answer 17

CnH2n

Question 18

These isomers have atoms connected in the same order but different 3D orientation.

Answer 18

stereoisomers

Question 19

Strain caused by bond angles forced to deviate from ideal 109 degrees.

Answer 19

angle strain

Question 20

Larger substituents experience greater steric hindrance and are happier in the ___ position.

Answer 20

equatorial

Question 21

the consequence of the tetrahedral stereochemistry of sp3-hybridized C atoms. Sp3 hybridized C atoms with 4 unique substituents have this quality.

Answer 21

handedness

Question 22

non-superimposable mirror images which come in pairs

Answer 22

Enantiomers

Question 23

a molecule that is superimposable on it’s mirror image is

Answer 23

achiral

Question 24

a molecule that is not identical to its mirror image is said to be

Answer 24

chiral

Question 25

if a molecule has a plane of symmetry it is

Answer 25

achiral

Question 26

an enantiomer which rotates light counter clockwise is labeled negative and is called

Answer 26

levorotatory

Question 27

an enantiomer which rotates light clockwise is labeled positive and is called

Answer 27

dextrorotatory

Question 28

the extent to which an enantiomer rotates light is dependent on

Answer 28

the # of optically active molecules in the sample

Question 29

when ranking atoms to determine configuration, atoms are ranked by their __

Answer 29

atomic number

Question 30

R configuration

Answer 30

a clockwise path from atom 1 to 3 around the chiral center

Question 31

s configuration

Answer 31

a counter clockwise path from atom 1 to 3 around the chiral center

Question 32

Optical rotation sign (is/is not) related to R/S configuration.

Answer 32

IS NOT

Question 33

This stereoisomer is oppositely configured at every chiral center.

Answer 33

Enantiomers

Question 34

This stereoisomer is identical except for 1 chiral center

Answer 34

epimer

Question 35

this stereoisomer is oppositely configured at some chiral centers

Answer 35

diastereomer

Question 36

a molecule which contains chiral centers but do have a plane of symmetry. These molecules do not rotate polarized light.

Answer 36

meso compound

Question 37

a 50:50 mixture of enantiomers

Answer 37

racemic mixture, a racemate