Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CHM 256 > Unit 1 > Flashcards

Unit 1 Flashcards

1
Q

How do you determine the number of unsaturations from a structure?

A

Generally, 1 unsaturation per ring per double bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Formula for # of unsaturations

A

C -1/2H +1/2N +1 -1/2X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Toluene

A

Benzene w/ a methyl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Phenol

A

Benzene w/ an alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Analine

A

Benzene w/ an amino group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Benzaldehyde

A

Benzene w/ am aldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Benzoic acid

A

Benzene w/ a carboxylic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Anisole

A

Benzene w/ OCH3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Benzene as a substituent

A

Phenyl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you know which carbon is C1?

A

the parent structure gets C1 or the 1st alphabetical substituent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does M+2 mean in mass spectrometry?

A

There are isotopes of either Br or Cl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the Br isotopes? What ratio do they occur in?

A

79Br : 81Br
1 : 1 ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the Cl isotopes? What ratio do they occur in?

A

35Cl : 37Cl
3 : 1 ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

List the atomic weights of CHON?

A

C 12
H 1
O 16
N 14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List the cations in order of most stability?

A

benzyl ~ alyllic > tertiary > secondary > primary > methyl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do unbranched alkanes fragment?

A

They form a series of cations differing by 14 amu. Note: no methyl cation forms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do branched alkanes fragment?

A

Fragmentation occurs to give secondary and tertiary cations.

18
Q

How do cycloalkenes fragment?

A

Fragmentation occurs to give a loss of side chains and a loss of ethylene from the ring.

19
Q

What does a loss of 28 amu mean in mass spec?

A

There is a cycloalkene that has lost ethylene, breaking up the cyclo part.

20
Q

How do alkenes fragment?

A

Will show strong molecular (parent) ion peak.
Alyllic cations will form, NOT vinyl cations.
charge on neighboring carbon, NOT on double bond

21
Q

How do alkynes fragment?

A

Will show strong molecular ion peak
Will form propargyl cation (charge on neighboring carbon), NOT on triple bond

22
Q

How do alcohols fragment?

A
  • loss of H2C=O+H
    -loss of H2O, taking H from 3rd carbon away
23
Q

How do benzene derivatives fragment?

A

Benzyl cations will form with M=91

24
Q

How do aldehydes fragment?

A
  • aldehyde cation will break off (-29 amu)
  • loss of hydrogen (-1 amu)
25
Q

What does M=39 mean?

A

triple bond with charge on neighboring carbon

26
Q

What does M=41 mean?

A

allylic ion (double bond with charge on neighboring carbon)

27
Q

What does deshielded mean?

A

Electron deficient environment / more aromatic

28
Q

Define integration value for NMR?

A

the relative area under an integration curve and the number of specific H’s

29
Q

Define splitting patterns in NMR

A

the multiplicity (number of lines of a proton signal) induced by neighboring protons.
n+1 rule

30
Q

As the amount of conjugation/neighboring double bonds on a molecule increases…

A

lambda max increases

31
Q

What’s the 1st step when analyzing IR spectra?

A

Check if there is a carbonyl present around 1800-1600

32
Q

How many cm^-1 is a carbonyl peak?

A

1820-1660

33
Q

How many cm^-` is an alcohol IR peak?

A

~3000

34
Q

How many cm^-` is an ester C-O stretch peak?

A

around 1300-1000

35
Q

How do you check for anhydride in IR?

A

two C=O absorptions around 1800

36
Q

How many cm^-1 is an amine IR peak?

A

3500

37
Q

How many cm^-1 is an alkene IR peak?

A

Around 1600

38
Q

How many cm^-1 are aromatic IR peaks?

A

Above 1450 and above 3000

39
Q

How many cm^-1 is a cyano IR peak?

A

Sharp 2250

40
Q

How many cm^-1 is an alkyne IR peak?

A

2000-3000

41
Q

Hydrocarbon IR peaks are…

A

To the right of 3300 and some at 1450

CHM 256 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions