Nomenclature Flashcards
What is molecular formula?
- The actual number of atoms present in a molecule.
Empirical formula def?
- Simplest whole number ratio of number of atoms in a compound.
Structural formula def?
Example of this in pink hand folder.
- Arrangement of atoms in a molecule without showing any bonds (WILL SHOW DOUBLE BONDS.)
How do you show side- branches in skeletal formula?
Example of this in pink hand folder.
- You put the atoms involved in the side branches in brackets.
Skeletal formula def?
- Shows carbon bonds as a skeleton (each point represents carbon atom.) Hydrogen/ carbon atoms aren’t shown but functional groups are.
Why is skeletal formula useful?
- Simple/ quick way of drawing structure of very complicated organic compounds.
How do you draw skeletal formula? What if you have double bonds?
Example of this in pink hand folder.
- Count how many carbons there are in hydrocarbon chain.
- Draw points with pencil (each point represents a carbon atom.)
- Any double bonds will flatten out/ have double line rather than just one
Example of this in pink hand folder.
Displayed formula def?
- Shows the arrangement of atoms: showing all the bonds and atoms in the molecule.
General formula def?
- An algebraic formula that can be applied to the same “family” of molecules.
What is a homologous series?
- A homologous series is a group/ series of compounds that have the same functional group and general formula.
Finish sentence
Successive members of homologous series increase by ……..
- CH₂
- (Ie. Methanol–> CH₃OH/ ethanol –> CH₃CH₂OH ) CH₂ is added (in structural formula) anywhere in the MIDDLE of the fomula (doesn’t need to be in a particular position, just not at beginning/ end of the molecule.)
What do aldehydes end in?
- al
(ie. proponal.)
What do ketones end in?
-one.
(Ie. propanone)
What do halogenalkanes’ name start with?
- Either: fluoro/ chloro/bromo/ iodo
What is the suffix and prefix for cycloalkanes?
Cyclo ………… ane
(Ie. Cyclopentane)
What do branched alkanes in hydrocarbon chains end with?
- alkyl (ie. yl)
- (Ie. Methyl group)
What are the different prefixes for number up to 6?
1- meth
2- eth
3- prop
4-but
5- pent
6- hex
What are molecules named according to?
- Named according to rules set by IUPAC (international rules!)
What are the steps for naming an unknown molecule with functional group?
1.) Find the longest continuous carbon chain in the molecule. Count the number of carbon atoms to deduce the stem for molecule (ie buta - for 5.)
2.) Functional groups will tell you end name of the molecule.
3.) Number the carbon chain so that the functional group sits on the lowest number carbon.
4.) Put the number the functional group is attached to infront of the ending of the name ie. 2- oic acid.
5.) Side chains/ unimportant functional groups written as prefixes (at start of molecule) in alphebitical order
6.) If there is more than one identical functional group/ side chain put the prefixes required!!
When deciding where the longest continuous chain of carbon atoms are in the molecule, does it matter whether the carbon atoms are in a straight line or not?
- No!
- It can be branched multiple times even!!
When naming molecule, if you have more than one (either 2/3/4) functional group/ side- chain what should you put in front of the name you have given it?
-2: di
- 3: tri
- 4: tetr
If you don’t have functional group on hydrocarbon chain, how would you number the carbon atoms in the longest carbon atom chain? What if you have multiple alkyl groups?
- You number carbon atoms so that your alkyl group (side chain) is attached to the lowest number carbon atom in the chain.
- Multiple alkyl groups –> you want the lowest combination of numbers (ie. 2-ethyl, 3-methyl would be chosen over 4-ethyl, 5-methyl.)
() - extra info for clarification.
What do alcohols end in?
- ol.
What do carboxylic acids end in?
- oic acid.
What order are side chains/ less important functional groups written in when naming the molecule?
- Side chains/ less important functional groups at beginning of the molecule.
- In ALPHABETICAL ORDER!! Ie. if you had methyl (on carbon 1) and ethyl (on carbon 3) side branches you would write 1-methyl, 3- ethyl……..
If two numbers are next to each other on your line when naming your molecule, what must you separate those two numbers by?
- Separate the numbers by a coma.
- (Ie. 3-methylbutan-1,1diol)
What is functional group of esther? What do esters end in?
- COO
- anoate.
What is the functional group of aldehydes? How would you WRITE the functional group?
–CHO
- CANNOT FLIP THE H AND O around when writing it!! (because then you wouldn’t know for certain whether it’s an alcohol or not.)
() - extra info for clarification
What is functional group of ketone?
CO
If you have two OH functional groups attached to the SAME C atom (ie. carbon-1) , how would you write this at the end of the molecule name ?
1,1 - diol
(two 1’s shows that there are 2 functional groups LOCATED ON THE SAME CARBON!!)
If I have a side-chain of methyl group on carbon 3 and a side chain of ethyl group on carbon 2- how would I write this (at the beginning of name of molecule) when naming the molecule? Why do I write the side-chains in this way?
- 2- ethyl- 3- methyl ………
- They are written in alphabetical order.
If I have a molecule with longest carbon chain horizontally (with 5 carbon atoms) and you can have the same length carbon chain by including carbon of a side chain, would your numbering be different?
- No.
- In most cases, the numbering will be the exact same ie. the number that the particular functional/ alkyl group is attached to will be the same either way.
If I don’t have a functional group on my molecule, only one ethyl and one methyl group, how do I number the carbon atoms in the longest carbon chain?
- Number carbon atoms so that you have the lowest combination of numbers in front of methyl/ ethyl group name.
- (Ie. if you had to pick between 2-ethyl, 3-methyl AND 4-ethyl, 5-methyl, you would pick the first because it is the lowest combination of numbers. )
() - extra info for clarification.
When we do skeletal formula, we don’t include carbons/ hydrogens in hydrocarbon chain but WHAT WOULD WE INCLUDE?/ HOW WOULD WE INCLUDE IT?
- Any functional groups (make sure it’s pointing away from the V ie. not going inwards.)
- Halogens (draw two halogens on one carbon atom/ point how it is on diagram draw on sheet of paper in folder!!)
- Any oxygens (ie. in ketones/ aldehydes.)
(diagram- on sheet of paper- in pink hand folder/ on wall if needed)
Where exactly do we include the dashes and the commas when writing name of molecule? Where would we NOT include them?
- Dashes: between any letter and number.
- Commas: between two numbers that are next to each other.
- Do not include them between two words (just write the words next to each other directly ie. 3-hydroxybutanoic acid.)
- THIS IS EXTREMELY IMPORTANT TO GET RIGHT!!
What functional group always takes priority/ will always have its suffix as the end part of name of molecule even if there are other functional groups present?
- Carboxylic acid.
If a molecule has OH functional group/ COOH functional group, how do we name it?
- The OH becomes a hydroxy group.
- The COOH = (priority group) so the name will end in oic acid!!
Why don’t we have to put a number infront of aldehydes (ie infront of the al) and in front of carboxylic acids (ie. in front of the oic acid?)
- Because these functional groups will always be on carbon 1.
Give name of this molecule: CH₃CH=CHCH₂CH₂OH
- pent-3-en-1-ol.
Functional group of nitrile? What is suffix of nitrile?
C (triple bond) N
Nitrile (ie. propanenitrile.)
Functional group of amine?
Prefix/ suffix for amine?
- NHH (anywhere in the chain!!)
- Prefix: amino. Suffix: amine.
What do we always try to include in our longest carbon chain?
- Try to include functional group (if functional group contains carbon, obviously!!)
() - extra info for clarification.
What name would you give molecule that has alkene functional group (C=C double bond) and carboxylic acid functional group?
Name ending: Enoic acid
What name would you give molecule that has alcohol functional group and nitrile functional group?
hydroxynitrile.
Is it butane-2,3-diol OR butan-2,3-diol? Which is correct?
Butane-2,3-diol is CORRECT!!
