Chapter 11- Introduction to Organic Chemistry Flashcards
What is an empirical formula?
Formula showing simplest integer ratio of atoms of each element in a compound.
What is a molecular formula?
Formula showing actual number of atoms of each element in a compound.
What formulae other than molecular formulae and empirical formulae are there?
Structural, displayed, skeletal
What are the first six roots in IUPAC naming?
meth-
eth-
prop-
but-
pent-
hex-
What is the functional group and suffix for alkenes?
C=C double bond
-ene
What is the functional group and suffix for alkanes?
C-C bonds (no double bonds)
-ane
What is the functional group and suffix for ketones?
C=O
-one
What is the functional group and suffix for alcohols?
-OH
-ol
What is the functional group and suffix for aldehydes?
-COH
-al
What is the functional group and suffix for carboxylic acids?
-COOH
-oic acid
What is the functional group and PREfix for haloalkanes?
R-X (X = F, Cl, Br, I)
fluoro-
chloro-
bromo-
iodo-
How is the position of a side chain or functional group shown?
A number (locant) is used to give its position along the chain.
Carbon atoms in the chain are numbered (so that name has lowest total) and the number goes before the functional group, eg 2- bromo-.
For C=C bond, the number of the atom which it COMES from is given.
How is the number of side chains or functional groups shown?
Prefix included showing the number:
di- 2
tri- 3
tetra- 4
How are the side chains and functional groups ordered in the name?
Alphabetically, ignoring prefixes like di, tri, tetra.
What are side chains of different lengths called?
1: methyl-
2: ethyl-
3: propyl-
4: butyl-
What is a homologous series?
A family of organic compounds with the same functional group but different carbon chain length.
How does carbon chain length of a homologous series affect properties?
Physical: Melting, boiling point increases as number (and strength) of VdW forces increases. -Volatility, flammability decreases, viscosity increases
Has little effect on the chemical reactivity of the functional group.
How does chain branching affect melting point?
Reduces melting point as the molecules pack together less well.
What does a curly arrow show?
The movement of electrons. Double headed arrow shows a pair, single headed shows one.
Moves from a covalent bond or lone pair of electrons to a positively charged area.
What are structural isomers?
Molecules with the same molecular formula but different structural formulae.
What are the three types of structural isomer?
Chain, positional and functional group isomers
What are positional isomers?
Molecules with the same functional group but in different positions,
eg but-1-ene and but-2-ene
What are functional group isomers?
Molecules with the same molecular formula but different functional groups,
eg C5H10 as pent-1-ene or cyclopentane
What are chain isomers?
Molecules with the same molecular formula but different carbon chain lengths,
eg butan-1-ol and 2-methylpropan-1-ol
What are stereoisomers?
Molecules with the same structural formula but different arrangements of bonds in space, eg optical and E-Z isomers
What are E-Z isomers?
Molecules in which the substituents either side of a C=C bond are the same but in different positions.
They can be the same side (Z) or opposite sides (E).
Why are there E-Z isomers?
There is restricted rotation about a planar carbon-carbon double bond so the E and Z isomers are separate compounds.
What are the Cahn-Ingold-Prelog (CIP) priority rules used for and what are they?
To determine whether an isomer is E or Z, we must know the priority group on each side of the bond.
The CIP rules say that the substituent on each side with the highest mass is the priority group. If the atoms have the same mass, go along the chain until it differs.
What is a free radical?
A species with an unpaired electron. They are extremely reactive.
(When a covalent bond splits homolytically, one electron goes to each atom that was originally bonded so they now each have an unpaired electron)
What are the three stages in a free-radical substitution?
Initiation, propagation, termination
What is the initiation step in free radical substitution?
Cl-Cl bond broken under exposure to UV light.
Bond broken homolytically so one electron goes to each Cl atom, forming 2 chlorine free radicals
What is a necessary condition to start the free radical substitution chain reaction?
UV light which breaks the Cl-Cl bond
What are the two steps in the propagation step?
Free radical takes H atom from CH4 forming HCl and making CH4 now a free radical: .CH3
.CH3 then reacts with Cl2 to form CH3Cl leaving a free radical (chain reaction, free radical formed again)
What is the termination step?
End step in which free radicals are removed
Any two free radicals react to form a stable compound, eg 2Cl. –> Cl2
