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Chemistry 6 - Organic Chemistry > Nomenclature > Flashcards

Flashcards in Nomenclature Deck (23)
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1
Q

how would you write the number of carbon atoms for a molecule

A
  • by using a letter code

- like meth = one carbon atoms or prop = three

2
Q

what is the mnemonic for the first five number of carbon atoms

A
  • Monkeys Eat Peeled Bananas (Partially)
  • M = meth = one carbon atom
  • E = eth = two carbon atoms
  • P = prop = three carbon atoms
  • B = but = four carbon atoms
  • P = pent = five carbon atoms
3
Q

why are suffixes and prefixes used when naming molecules

A
  • to indicate the presence of atoms other than carbon and hydrogen
4
Q

how would a suffix or prefix be written with 2 examples

A
  • by adding other letters before or after the code for the number of carbon atoms
  • like bromo = an atom of bromine, making bromoethane
  • or ol = a hydoxyl group (OH) at the end of alcohols
5
Q

why would you need to multiply prefixes and are the common ones

A
  • to show the presence of two or more identical groups

- usually with di or tri = two or three

6
Q

what are locants

A

where atoms and groups can have different positions in a molecule

7
Q

what are used to show the positions of locants in the name of a molecule

A

numbers and hyphens

8
Q

what do the numbers used to show locants specifically indicate

A

the carbon atom in the longest chain that the group is attached to

9
Q

what would a locant of 2- be telling us

A
  • that the group of atoms are attached to the second carbon atom
  • in the longest chain of carbon atoms
10
Q

what are the codes and prefixes for the number of carbon atoms up to 5

A
  • meth = methyl
  • eth = ethyl
  • prop = propyl
  • but = butyl
  • pent = pentyl
11
Q

what is the name of CH3-CH2-CH3

A

propane

12
Q

what is the name of CH3-CH-CH3
|
CH3

A

methylpropane

13
Q

why doesnt that methylpropane have a 2- at the beginning of it to show the locant

A
  • if the methyl group was attached to the first or third carbon atom
  • that would simply make a chain 4 carbon atoms long
  • making it butane
  • therefore the locant isnt needed at that is the only position the methyl could be in for the code to still be prop(ane)
14
Q

what is the name of CH3-CH2-CH-CH2-CH3
|
CH3
and why

A

3-methlypentane

  • the longest chain consists of 5 carbon atoms
  • and the methyl is attached to the third carbon atom
  • this time the locant can be shown because the code wouldnt change if it was bonded to the 2nd or 4th carbon atom
15
Q

what is the name of CH3-CH2-CH2-CH-CH3
|
CH3
and why

A

2-methylpentane

  • it is not 4-methyl as the lowest locant should be used
  • considering 4 and 2 would both indicate exactly the same molecule
  • just flipped over
16
Q
what is the name of:
        CH3
          |
CH3-CH-CH-CH3
                 |
              CH3
and why
A

2,3-dimethylbutane

  • there are two locants showing where two of the methyl molecules are
  • the numbers should be in chronological order from the smallest if it is the same prefix
  • because there are two you multiply the prefix to dimethyl
  • and the longest chain that can be made consists of 4 carbon atoms so it is butane
17
Q
what is the name of:
                  CH2-CH3
                     |
CH3-CH2-CH-CH-CH3
                         |
                      CH3
and why
A

3-ehtyl-2methylpentane

  • the prefixes must be in alphabetical order if they are different
  • it is not 4methyl as that isnt the smallest number
  • and 3 + 4 is higher than the number of carbon atoms making the longest chain(5) which would be 3 + 2
18
Q

what is the name of CH3-CH2-OH

A

ethanol

19
Q

what is the name of CH3-CH2-CH2-OH

A

propan-1-ol

20
Q

what is the name of CH3-CH-CH-CH3
| |
OH CH3

A

3-methylbutan-2-ol

  • it is not 2-methylbutan-3-ol because the lowest locant should be used for the suffix over the prefix
  • as the suffix indicates the functional group
21
Q
what is the name of:
       CH3
         |
CH3-C-CH2-CH2-OH
         |
       CH3
and why
A

3,3-dimethylbutan-1-ol

  • the use of prefixes, suffixes and a comma is kinda long
  • the suffix comes first so its 1 going from right to left
  • the two methyl molecules are bonded to the 3rd carbon atom in this direction
  • so the multiplied prefix is dimethyl and you have one on the 3rd twice
  • giving 3,3
22
Q

what would dimethylpropane look like

A
CH3
          |
CH3-C-CH3
          |
       CH3
23
Q

what would 3-methylbutan-1-ol look like

A

CH3-CH-CH2-CH2-OH
| |
CH3 (OH) or this