Organic 1 - Chapter 11: Introduction to Organic Chemistry Flashcards
List all the different chemical formulae
Empirical formula
Molecular formula
Displayed formula
Structural formula
Skeletal formula
Describe the empirical formula
Simplest ratio of the atoms of each element present in a compound
Describe the molecular formula
Actual number of atoms of each element in the molecule
Describe the displayed formula
Shows every atom and bond in the molecule
Describe the structural formula
Shows the arrangement of atoms in a molecule written out
Describe the skeletal formula
Requires verification
Carbon atoms aren’t drawn. Straight lines represent C-C bonds and carbon atoms are assumed to be where bonds meet. Hydrogen or C-H bonds aren’t drawn as each carbon atom is assumed to make a total of 4 bonds
What does a solid triangle (wedge) show in a 3D structural formula?
Bonds coming out of the paper
What do dashed lines show in a 3D structural formula?
Bonds going into the paper
What do curly arrows show?
The movement of a pair of electrons
What is a free radical?
The product of some covalent bonds breaking in a way where each of the original atoms that formed the bond get one electron each. The unpaired electrons from these are free radicals and are super reactive
What are the IUPAC for nomenclature
Simplified points yet to replace this
Identify the longest carbon chain. This chain is called the parent chain.
Identify all of the substituents (groups appending from the parent chain).
Number the carbons of the parent chain from the end that gives the substituents the lowest numbers. When comparing a series of numbers, the series that is the “lowest” is the one which contains the lowest number at the occasion of the first difference. If two or more side chains are in equivalent positions, assign the lowest number to the one which will come first in the name.
If the same substituent occurs more than once, the location of each point on which the substituent occurs is given. In addition, the number of times the substituent group occurs is indicated by a prefix (di, tri, tetra, etc.).
If there are two or more different substituents they are listed in alphabetical order using the base name (ignore the prefixes). The only prefix which is used when putting the substituents in alphabetical order is iso as in isopropyl or isobutyl. The prefixes sec- and tert- are not used in determining alphabetical order except when compared with each other.
If chains of equal length are competing for selection as the parent chain, then the choice goes in series to:
a) the chain which has the greatest number of side chains.
b) the chain whose substituents have the lowest- numbers.
c) the chain having the greatest number of carbon atoms in the smaller side chain.
d)the chain having the least branched side chains.
A cyclic (ring) hydrocarbon is designated by the prefix cyclo- which appears directly in front of the base name.
What is a homologous series?
A family of organic compounds with the same functional group but different carbon chain length
What properties do members of the same homologous series share?
The same general formula
Same functional group
Similar chemical properties
Length of the carbon chain has little effect on the chemical reactivity
Length of carbon chain effects physical properties like MP,BP and solubility
How does MP and BP change with carbon chain length?
They increase because intermolecular forces increase
How does branching affect MP and BP?
(answer requires verification)
BP: Branching decreases the BP due to reduced SA and weaker intermolecular forces
MP: Branching generally lowers the MP as they cannot pack as closely but there are exceptions
What is an isomer?
Molecules with the same molecular formula but different arrangement of atoms
List all types of structural isomerism
Positional isomerism
Functional group isomerism
Chain isomerism
What is positional isomerism?
Same functional group attached to the main chain but at different points
What is functional group isomerism?
Different functional groups
What is chain isomerism
Different arrangement of the hydrocarbon chain (e.g branching)
What is stereoisomerism?
2 or more compounds have the same structural formula. They differ in the arrangement of bonds in space
What are the 2 types of stereoisomerism?
E-Z isomerism
Optical isomerism
Optical isomerism is covered in C25.2
What is the difference between E-Z isomerism?
Positions of substituents at either side of a C=C bond either on the (Z) same side or (E) opposite side
When does E-Z isomerism occur and why?
In a double bond. Substituted groups cannot rotate around them.
They can occur in rings too for a similar reason, though this may not be part of the specification
Why can E-Z isomerism not occur in a single bond?
Substituted groups can rotate around them
E-Z isomerism also doesn’t occur in a triple bond but this is because of it’s linear geometry eliminating the possibility of the different spatial arrangements necessary for E-Z isomerism.
