Quiz 1

Question 1

how do you produce a compound with just single bonds from a terminal alkyne

Answer 1

H2, Pd/C

Question 2

how do you produce a compound with X on the most substituated carbon and a double bond on the terminal position from a terminal alkyne

Answer 2

HX where X = Cl, Br, or I

Question 3

how do you produce a compound with only single bonds and two Xs located on the same carbon from a terminal alkyne

Answer 3

xs HX

Question 4

how do you produce a compound with a double bond on the terminal position and one X is on one of the double bonded carbons, while the other X is on the other double bonded carbons from a terminal alkyne

Answer 4

Br2 or Cl2

Question 5

how do you produce a compound with just single bonds and two Xs on one carbon and two Xs on the other carbon from a terminal alkyne

Answer 5

xs Br2 or Cl2

Question 6

how do you produce a compound with the triple bond and a new R group formed from a terminal alkyne

Answer 6

1. NaNH2
2. RCH2Br

Question 7

how do you produce an aldehyde (double bond on oxygen) from a terminal alkyne

Answer 7

1. 9-BBN
2. H2O2, HO-

Question 8

how do you produce a ketone from a terminal alkyne

Answer 8

H2O, H2SO4

HgSO4

Question 9

how do you reduce a compound from a triple bond to a double bond for a terminal alkyne

Answer 9

H2

Lindlar catalyst

Question 10

how do you produce a compound with just single bonds from a internal alkyne

Answer 10

H2, Pd/C

Question 11

how do you produce a ketone from an internal alkyne

Answer 11

1. BH3
2. H2O2, HO-

Question 12

how do you produce a compound with an internal double bond and an X on one of the double bond carbons, while the other X is on the other double bonded carbon from an internal alkyne

Answer 12

Br2 or Cl2

Question 13

how do you produce a compound with just single bonds and two Xs on one carbon and two Xs on the other from a internal alkyne

Answer 13

xs Br2 or Cl2

Question 14

how do you produce a compound with an internal double bond and an X bonded to one of the carbons from an internal alkyne

Answer 14

HX

Question 15

how do you produce a compound with just single bonds and two Xs bonded to one internal carbon from an internal alkyne

Answer 15

xs HX

Question 16

how do you produce a cis alkene from a internal alkyne

Answer 16

H2

Lindlar catalyst

(syn addition)

Question 17

how do you produce a trans alkene from an internal alkyne

Answer 17

Na or Li, NH3

(anti addition)

Question 18

how to turn a terminal alkyne to an internal alkyne

Answer 18

adding the group you want (THE TRIPLE BOND STAYS AS A TRIPLE BOND)

1. NaNH2
2. RCH2Br

Question 19

how to turn an internal alkyne to a terminal alkene

Answer 19

ozonolysis: cuts the double bond in half and puts an oxygen on the double bond, turning it into a aldehyde

1. O3
2. Zn, CH3CO2H

Question 20

what is acetylene

Answer 20

H-C triple bond C-H

Question 21

how do you produce a compound with just single bonds and an OH bonded to an internal carbon from a terminal alkene

Answer 21

H2O, H2SO4

Question 22

how do you produce a compound with just single bonds and an OH bonded at the end from a terminal alkene

Answer 22

1. BH3
2. H2O2, HO-

Question 23

how do you produce a compound with just single bonds and an X bonded to an internal carbon, and another X bonded to the other carbon from a terminal alkene

Answer 23

Br2 or Cl2

Question 24

how do you produce a compound with just single bonds and an OH bonded to an internal carbon, and another X bonded to the other carbon from a terminal alkene

Answer 24

Br2 or Cl2

H2O

Question 25

Characteristics of a triple bond

Answer 25

- bond angle of 180 degrees - short carbon carbon bond of 120 A (very short) - strong bond of 231 kcal/mol (very strong)

Question 26

rank the stability of carbocations from MOST to LEAST stable

Answer 26

Most - tertiary carbocation - secondary carbocation - secondary vinylic cation (ab the same stability as the next one) - primary carbocation - primary vinylic cation (about the same stability as the next one) - the methyl cation Least

Question 27

dihalide vs. tetrahalide

Answer 27

dihalide: one halide (Br or Cl) group tetrahalide: two halides on one carbon (AKA geminal)

Question 28

why do two halides end up on the same carbon?

Answer 28

to improve stability (e- sharing)

Question 29

keto-enol tautomerism

Answer 29

to produce a ketone, an enol is formed first (instead of an O double bond, it has an OH group), but the enol is nearly impossible to isolate.

Question 30

tautomerism

Answer 30

are structural isomers (constitutional isomers) of chemical compounds that readily interconvert (differ by the location of a double bond and a hydrogen atom)

Question 31

internal vs. terminal for need of a catalyst or not and why

Answer 31

internal: no need for a catalyst terminal: needs a catalyst to help it get over the activity threshold since it's not as e- rich (the more alkyl groups present, the more e- they can donate). Terminal alkynes are also less reactive.

Question 32

why is a trans product produced?

Answer 32

because 9-BBN is so big it creates steric repulsion (the bulky groups go on opposite sides)

Question 33

high pKa vs. low pKa

Answer 33

low pKa = easy to remove proton (stronger acid) high pKa = difficult to remove proton (stronger base)

Question 34

ethyne pKa (HC triple bond HC)

Answer 34

25

Question 35

ethene pKa (H2C=CH2)

Answer 35

44

Question 36

ethane pKa (CH3CH3)

Answer 36

greater than 60

Question 37

why is the stability like this: alkyl group (sp3 hybridized) (least stable), a vinylic group (sp2 hybridized), and acetylide anion (sp hybridized) (most stable)

Answer 37

alkyl groups: 25 % s character vinylic groups: 33 % s character acetylide anion: 50 % s character

Question 38

pKa of H2O

Answer 38

15.7

Question 39

pKa of HF

Answer 39

3.2

Question 40

pKa of NH3

Answer 40

36