Ch. 3

Question 1

Acyclic Formula

Answer 1

Cn H2n+2

Question 2

Cyclic Formulas

Answer 2

Cn H2n

Question 3

Primary Carbon

Answer 3

Bonded to one C

Question 4

Secondary Carbon

Answer 4

Bonded to two Cs

Question 5

Tertiary Carbon

Answer 5

Bonded to three Cs

Question 6

Quarternary Carbon

Answer 6

Bonded to four Cs

Question 7

Constitutional Isomers

Answer 7

Differ in the way the atoms are connect to each other

Question 8

IUPAC Rules

Answer 8

1. FInd the longest chain of carbons and use it as the base
2. Name the attached groups using the location of each alkyl group by the number of the Carbon it’s attached to
3. Write alkyl groups in alphabetical order regardless of their position on the chain

Question 9

Naming Alkyl Groups (1 Carbon to 5 Carbons)

Answer 9

Methane, ethane, propane, butane, pentane

Question 10

Iso grouping

Answer 10

When the Cs form a triange
CH3
CH –
CH3

Question 11

Newman Projections – Eclipsed

Answer 11

The two molecules are almost on top of each other. Causes steric crowding and is high in energy

Question 12

Newman Projections – Staggered

Answer 12

The Hs are is spread out equally. Less steric crowding, lower in energy

Question 13

Keq equation (energy)

Answer 13

Keq = 10 ^ (± (3/2)∆E)

Question 14

What are the two Butane conformations and their angles?

Answer 14

Gauche (60° between methyls)
Anti (180º between methyls)

Question 15

HIgher alkanes resemble ______ in their preference for _____ and _____ conformations about the carbon-carbon bonds

Answer 15

Butane, anti and gauche

Question 16

Geometric Isomers

Answer 16

Same molecules connected to the same carbons, but one is cis and one is trans

Question 17

Cis molecule

Answer 17

The methyl groups are on the same side of the molecule

Question 18

Trans molecule

Answer 18

The methyl groups are on opposite sides of the molecule

Question 19

Cyclopentane ring strain

Answer 19

27 kcal/mol

Question 20

Cyclotetrane ring strain

Answer 20

26 kcal/mol

Question 21

Cyclohexane ring strain

Answer 21

0 kcal/mol

Question 22

Cyclopentane ring strain

Answer 22

6 kcal/mol

Question 23

cycloheptane ring strain

Answer 23

6 kcal/mol

Question 24

cyclooctane ring strain

Answer 24

9 kcal/mol

Question 25

cyclododecacane ring strain

Answer 25

5 kcal/mol

Question 26

Ring strain

Answer 26

A type of instability that exists when bonds in a molecule form angles that are abnormal

Question 27

In a cyclohexane, all the molecules are ____ so all bond angles can be ____ so there is no strain

Answer 27

staggered, 109.5°

Question 28

What directions do axial Hs on a chair conformation point?

Answer 28

Up and Down

Question 29

Which is more stable – equatorial or axial

Answer 29

equatorial because it has less steric crowding

Question 30

How do you interconvert two chairs?

Answer 30

switch axial and equatorial

Question 31

If there is an X group in the ____ position, it’s less stable because of ________

Answer 31

axial; steric crowding

Question 32

In cis/trans decaline is locked into one confomer, but a cis/trans decaline can ring flip

Answer 32

trans; cis

Question 33

Fused rings

Answer 33

Share two adjacent carbon atoms and the bond between them

Question 34

Bridged rings

Answer 34

Share two nonadjacent carbon atoms and one or more carbon atoms (the bridge) between them

Question 35

Spirocyclic compounds

Answer 35

Two rings share only one carbon

Question 36

What fusion does a cis or trans-decalin have? Which is more stable

Answer 36

The second ring is attached by two cis or trans bonds. Trans is more stable because the alkyls are equatorial