Ochem Exam #2

Front 1

What is a carbocation

Back 1

electrophiles that readily accept electron pairs. a carbon that does not have an octet, it has 3 bonds and a + charge. It is a temporary, high energy, short lived, intermediate

Front 2

which Eactivation is faster? 60 kj/mol or 80 kj/mol

Back 2

60--> lower means faster, higher means slower

Front 3

what is a transition state?

Back 3

structure occurring at an energy maximum

Front 4

what is an intermediate?

Back 4

energy minimum between 2 transition states

Front 5

in an energy diagram, if products are higher than reactants, this means what

Back 5

energy absorbed, energy change is positive

Front 6

in an energy diagram, if products are less than reactants, this means what

Back 6

energy released, energy change is negative

Front 7

When adding H2 to an alkene, how are the H's added? (same side or opposite sides)

Back 7

same side

Front 8

When you add H-X to an alkene, what side do you add the H to? the one with more H's or the side with more substituents?

Back 8

side with more H's

Front 9

When adding H20 to an alkene, what kind of catalyst do you need?

Back 9

Acid

Front 10

When adding H20 to an alkene, what is a product formed?

Back 10

Alcohol

Front 11

What happens to an alkene when you add KMnO4 and a base?

Back 11

2 OH's added across C=C in Syn (cis) fashion

Front 12

What happens to an alkene when you add KMnO4 and H2O?

Back 12

No reaction to an alkene

Front 13

What happens to an alkene when you ad KMnO4 and an acid?

Back 13

"shreds" the C=C in half

Front 14

What is Stereochemistry?

Back 14

Analysis of molecules that are different ONLY in their three dimensional arrangements

Front 15

What does Chiral mean?

Back 15

An object that is different that its mirror image. It has a "handed-ness" A left and right hand.

Front 16

What does Achrial mean?

Back 16

An object that is identical to its mirror image (ex: sock, coffee mug)

Front 17

What do you use as a catalyst for a hydroxylation/oxidation rxn?

Back 17

KMnO4

Front 18

When doing hydroxylation/oxidation with a base, what is added to the alkene? And in what fashion? (trans, cis?)

Back 18

2 OH's in cis fashion

Front 19

What do you use as a catalyst when doing hydrogenation?

Back 19

Pd or Pt

Front 20

What do you use as a catalyst when doing a Hydration rxn?

Back 20

An aqueous acid (example: H3PO4)

Front 21

What is the catalyst for transforming a Benzene to having one SO3H on the ring?

Back 21

H2SO4/SO3

Front 22

What is a Polymer?

Back 22

Molecule built up by repeating smaller molecules

Front 23

When doing a hydroxylation/oxidation rxn with an acid, if 1 hydrogen is connected to the carbon, what forms? What will you need to do?

Back 23

An Aldehyde is formed O=C--H
You will need to turn this into a Carboxylic Acid by adding an O to the H to turn into O=C--OH

Front 24

When doing a hydroxylation/oxidation rxn with an acid, if 2 hydrogens are present on the carbon, what forms? What will you need to do ?

Back 24

CO2+H2O
You will have O=C---H2. You need to add 2 O's to the H's. This gives you O=C---OH&OH

Front 25

Carbocation stability increases or decreases with increasing alkyl substitution?

Back 25

Increases

Front 26

What is Markovnikov's Rule?

Back 26

When adding HX to an alkene, the H attaches to the carbon with fewer alkyl substituents (more H's) and the X attaches to the carbon with more alkyl substituents

Front 27

What is an enantiomer?

Back 27

A stereoisomer that is identical to its mirror image

Front 28

What is a diastereomer

Back 28

Stereoisomers that are not mirror images

Front 29

What does achiral mean?

Back 29

Plane of symmetry, Identical to its mirror image

Front 30

When doing a hydration rxn, what is added to the alkene?

Back 30

An H and an OH

Front 31

What is added to an alkene when reacting with Br2 or Cl2?

Back 31

Add 2 Br's or 2 Cl's. Remember this is an alkene, not a benzene

Front 32

When doing a hydrogenation, what is added to the alkene? What fashion are they added in? (trans/cis?)

Back 32

Add 2 H's in cis fashion

Front 33

What catalyst is used to make a benzene into a benzene with just a NO2 connected?

Back 33

HNO3/H2SO4

Front 34

What catalyst is used to make a benzene into a benzene with just an O=C--R connected?

Back 34

O=C---R Cl /AlCl3

Front 35

What catalyst is used to make a benzene into a benzene with just an R group connected?

Back 35

R--Cl/AlCl3

Front 36

What catalyst is used to make a benzene into a benzene with just a Br connected?

Back 36

Br2/FeBr3

Front 37

What catalyst is used to make a benzene into a benzene with just a Cl connected?

Back 37

Cl2/FeCl3

Front 38

When doing a hydrogenation/oxidation rxn with an alkene, what happens?

Back 38

Breaks the alkene bond in half, add O's to broken ends.

Front 39

What does Chiral mean?

Back 39

having a "handed-ness"
L & R

Front 40

When KMnO4 reacts with a Benzene Ring, what happens?

Back 40

Any alkyl group (CH3, CH2CH#...) will oxidize into a Carboxylic Acid (sometimes making Benzoic Acid)

Front 41

Which reaction is faster? A reaction with an ortho/para director or a reaction with a meta director?

Back 41

Ortho/Para

Front 42

"Optically Active" Means _______

Back 42

Chiral

Front 43

If you have 3 stereocenters, it means that you have ______ stereoisomers

Back 43

2^3=8

Front 44

If you have 2 stereocenters, it means that you have ______ stereoisomers

Back 44

2^2=4

Front 45

What is the specific rotation of a sample that is 60% R -62degrees, and 40% S +62 degrees?

Back 45

(60% R -40% S =) 20% R
it will be negative
20% of -62degrees = .2x62= -12.4

Front 46

(Info given) R= -60degrees S=+60 degrees

you are given 75% S and 25% R
-What is the new net rotation?

Back 46

You will have a +50% R rotation

50% of 60 is 30, so you'll have a +30degree R rotation

Front 47

You are given a sample that has 50% S and 50% R for rotation. It has a net rotation of _____degrees, and is called ________

Back 47

0degrees of rotation
RACEMIC

Front 48

In seterochemistry, if S is a + degree, then R will be a ______ degree

Back 48

negative, -

Front 49

What is a Meso Compound

Back 49

A compound that is achiral (identical to mirror image) but also contains more than 1 stereocenter

Front 50

When you have a stereocenter that has arrangement priority going clockwise

Back 50

"R"

Front 51

When you have a stereocenter that had arrangement priority going counter-clockwise

Back 51

"S"

Front 52

What is the product of Toulene + KMnO4/H20?

Back 52

Benzene ring with COOH

Any Carbon directly connected to the aromatic ring and has at least 1 H connected to that Carbon will be oxidized to a Carboxylic Acid

Front 53

What happens to an alkyl group (CH3) on a Benzene ring when reacted with KMnO4?

Back 53

The Alkyl group will change into Carboxylic Acid

Any Carbon directly connected to the aromatic ring and has at least 1 H connected to that Carbon will be oxidized to a Carboxylic Acid

Front 54

What are examples of Meta Directors?

Back 54

-electronegativities
-O=C--R groups
-NO2
-CN

Front 55

What are examples of Ortho/Para directors?

Back 55

-Alkyl groups (CH3, CH2CH3...)
-Lone pair of electrons on site of attachment
-F, Cl, Br, & I