Organic Chemistry Flashcards
What is an organic molecule? What are the main sources of organic molecules?
- Organic molecule: Molecules containing Carbon atoms(that are generally covalently bonded to other carbon/hydrogen atoms)
- Can contain other atoms - Exceptions: Elemental Carbon(s), Oxides of carbon(ex. CO2, CO), Most ionic compounds(except CH3COONa)
- Sources of organic molecules: Living things, fossil fuels
What is a hydrocarbon?
Hydrocarbons are organic molecules containing only Carbon and Hydrogen
What is an alkane?
An alkane is a hydrocarbon that contains only single bonds.
What is a homologous series?
A homologous series is a series of molecules that contain one extra carbon in the parent chain than the molecule before
- Carbons have to connect to each other
- Ex. Ethane is part of the same homologous series as methane
What is a structural isomer? How can you determine if two molecules are structural isomers of each other?
Structural isomers have an identical molecular formula but a different structure.
How to determine structural isomers
-Name the molecule: If the names are different, you have two different isomers
- Units of saturation have to be the same(1 unit of saturation = 2 H’s missing from standard alkane)
- Same number of Carbons
What are the functional groups and their subgroups in organic molecules? Create a flow chart.
- Hydrocarbons
(a) Alkanes
(b) Alkenes
(c) Alkynes
(d) Aromatics - Organic Halides
What is a heteroatom?
A heteroatom is an atom that is not a C or H inside an organic molecule.
What are the three ways that an organic molecule can be drawn/expressed?
- Complete structural: All the C’s and H’s are written out with the bonds drawn between them
- Condensed structural: Only the letters; Condensed structural is based on the complete structural drawing and you write it out by going from left to write and then condensing the molecules you see(looking at the H’s connected to each carbon atom in the parent chain and also branches). Include subscripts if the same subset of molecules are right beside each other.
- Bond line notation
What are the three intermolecular forces?
- London Dispersion forces: Created by temporary dipoles caused by uneven spread of electron in the molecules. LDF is proportionate to the number of electrons in the molecule(more electrons = more LDF)
- Dipole-Dipole: Polar molecules with permanent dipoles
- Conditions for polarity: (1) molecules can’t be symmetrical(dipoles would cancel themselves out, (2) electronegative atoms need to be present - Hydrogen bons: H bonded directly to N, F, or O
What is the generic molecular formula for an alkane?
C(n)H(2n+2)
What are the physical properties of alkanes?
Physical Properties
- Have only LDF, so low melting and boiling points. As you go down homologous series, mp and bp increase as LDF increases
- Solubility: Like dissolves like
What are the chemical properties of alkanes?
Alkanes can combust and can participate in substitution reactions.
What determines solubility? What does “like dissolves like” mean?
- Non polar will dissolve non polar
- Polar without H-bonds will dissolve polar without H-bonds
- Polar with H-bonds will dissolve polar with H-bonds
What is the prefix for 2 carbons?
eth
What is the prefix for 1 carbon?
meth
What happens if there is a tie when numbering the parent chain(for alkanes, alkenes, and alkynes)?
The alphabetically lower branch gets the smaller number(ethyl would get lower number than methyl if there is a tie when numbering the branches)
What is the naming format/layout for branches ?
(Locant)-(Prefix for # of C’s)yl
If there are more than one of the same branches:
(Locant#1),(Locant#2)-(prefix)(# of C’s)yl
prefix: di, tri, tetra
What is the chemical formula for cycloalkanes?
C(n)H(2n)
How many hydrogens are lost for each extra feature(DB/TB/Cyclo)?
2 Hydrogens
how do you name an alkane?
- Find the longest chain of carbons, called the parent chain
- Number the parent chain so that the branches have the lowest # possible
- Name the branches in alphabetical order
(Locant)-(Prefix for # of C’s)yl - Name the parent chain
(# of carbons)ane
NO SPACE
List out the prefix’s for the number of carbons, to ten carbons.
1-meth
2-eth
3-prop
4-but
5-pent
6-hex
7-hept
8-oct
9-non
10-dec
What is the nomenclature for cycloalkanes?
Simple branching: ring is parent, number branches alphabetically
(branches)cyclo(#of carbons)ane
Ex. 1-ethyl-3-methylcyclopentane
Complex branching(when ring is not parent): alphabetize branches, REMEMBER THAT THE WORD “CYCLO” IS PART OF ALPHABETIZATION
Ex. 6-cyclopropyl-3-ethyl-4-methyloctane
What is an alkene?
A hydrocarbon with one of more double bonds between the carbons
What are the physical and chemical properties of cycloalkanes?
Same as SIMILIAR SIZED alkanes:
Physical Properties
- Have only LDF, so low melting and boiling points. As you go down homologous series, mp and bp increase as LDF increases
- Solubility: Like dissolves like
What are the physical and chemical properties of alkenes?
Physical: Have similar mp/bp etc. to similar sized alkanes because there is only LDF. If anything the mp/bp can be slightly higher. alkenes have low solubility in water and high solubility in a non polar solvent.
Chemical: Can combust and participate in addition reactions
What is the nomenclature of alkenes?
- DB has a higher priority than SB
Higher priority means:
-Parent chain is the lowest chain of carbons that contains the priority feature
-When numbering the parent chain, the priority feature gets the smallest number possible. If there is a tie, the branches get the lowest set if numbers possible. If there is another tie, alphabetization.
The branching nomenclature stays the same. The parent suffix changes:
for 1 DB: (# of C’s)-(locant)-ene
For <1 DB: (# of C’s)a-(locants)-(di/tri/tetra)ene
What is the nomenclature for a cycloalkene?
The double bond is always in position 1 or 2 so no locant required.
What is an alkene?
A hydrocarbon with one or more double bonds between carbons
Unlike single bonds, double bonds can have ______________(1) isomers. This is because ___________________(2).
(1) Geometric
(2) Single bonds can rotate while double bonds can not
What is the difference between cis and trans isomers?
Groups are connected to the double bond in opposite directions: trans isomers
Groups are connected to the double bond in same directions: cis isomers