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Chemistry 6 - Organic Chemistry > Nomenclature > Flashcards

Flashcards in Nomenclature Deck (23)
1

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

- by using a letter code
- like meth = one carbon atoms or prop = three

2

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

- 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

why are suffixes and prefixes used when naming molecules

- to indicate the presence of atoms other than carbon and hydrogen

4

how would a suffix or prefix be written with 2 examples

- 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

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

- to show the presence of two or more identical groups
- usually with di or tri = two or three

6

what are locants

where atoms and groups can have different positions in a molecule

7

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

numbers and hyphens

8

what do the numbers used to show locants specifically indicate

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

9

what would a locant of 2- be telling us

- that the group of atoms are attached to the second carbon atom
- in the longest chain of carbon atoms

10

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

- meth = methyl
- eth = ethyl
- prop = propyl
- but = butyl
- pent = pentyl

11

what is the name of CH3-CH2-CH3

propane

12

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

methylpropane

13

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

- 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

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

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

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

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

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

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

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

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

what is the name of CH3-CH2-OH

ethanol

19

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

propan-1-ol

20

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

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

what is the name of:
CH3
|
CH3-C-CH2-CH2-OH
|
CH3
and why

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

what would dimethylpropane look like

CH3
|
CH3-C-CH3
|
CH3

23

what would 3-methylbutan-1-ol look like

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