Nomenclature

Question 1

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

Answer 1

• by using a letter code

- like meth = one carbon atoms or prop = three

Question 2

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

Answer 2

• 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

Question 3

why are suffixes and prefixes used when naming molecules

Answer 3

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

Question 4

how would a suffix or prefix be written with 2 examples

Answer 4

• 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

Question 5

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

Answer 5

• to show the presence of two or more identical groups

- usually with di or tri = two or three

Question 6

what are locants

Answer 6

where atoms and groups can have different positions in a molecule

Question 7

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

Answer 7

numbers and hyphens

Question 8

what do the numbers used to show locants specifically indicate

Answer 8

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

Question 9

what would a locant of 2- be telling us

Answer 9

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

Question 10

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

Answer 10

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

Question 11

what is the name of CH3-CH2-CH3

Answer 11

propane

Question 12

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

Answer 12

methylpropane

Question 13

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

Answer 13

• 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)

Question 14

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

Answer 14

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

Question 15

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

Answer 15

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

Question 16

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

Answer 16

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

Question 17

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

Answer 17

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

Question 18

what is the name of CH3-CH2-OH

Answer 18

ethanol

Question 19

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

Answer 19

propan-1-ol

Question 20

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

Answer 20

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

Question 21

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

Answer 21

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

Question 22

what would dimethylpropane look like

Answer 22

CH3
          |
CH3-C-CH3
          |
       CH3

Question 23

what would 3-methylbutan-1-ol look like

Answer 23

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