Organics Flashcards
What is Substitution in relation to chemical reactions of Alkenes?
When one H atom is substituted for another atom.
What is an Addition reaction of Alkenes?
The C=C double bond breaks and small molecules add to the molecule.
Examples:
a) Alkene + H₂ → alkane
b) Alkene + Halogen → haloalkane
c) Unsymmetrical alkene + halogen halide (H’X’) → haloalkane
d) Alkene + water/dilute acid → alcohol
e) Addition Polymerisation
What is Markovnikoff’s Rule?
If the alkene and the reagent over the arrow are both unsymmetrical, then 2 PRODUCTS will be made in the addition reaction. We call these MAJOR and MINOR products.
Note: Sometimes this rule is referred to as ‘the rich get richer and the poor get poorer’. (Don’t say this in exam it’s not enough).
We can turn an __________ into an _________ if DILUTE ACID is used and this might involve MARKOVNIKOFF’S RULE too. This can be shown over the arrow as H₂O/H⁺ or written as dil. H₂SO₄
ALKENE
ALCOHOL
What is an Oxidation Reaction of an Alkene?
Where the alkene GAINS AN OXYGEN ATOM.
In an Oxidation Reaction of an Alkene what is the oxidising reagent?
PURPLE PERMANGANATE ION, MnO₄⁻
What condition is required in an oxidation reaction of an alkene?
ACID CONDITIONS (H⁺)
What is the product in an oxidation reaction of an alkene?
DIOL (ALCOHOL WITH 2 x OH)
What colour change is observed in an oxidation reaction of an alkene?
PURPLE to COLOURLESS
What distinguishing test is used for alkenes?
ALKENES will rapidly turn ORANGE BROMINE WATER (BR₂) colourless.
What will ALKANES do in ORANGE BROMINE WATER (BR₂)?
SLOWLY turn the BR₂ water colourless with UV light.
What are the 3 types of Isomers?
1) Constitutional/Structural Isomers
2) Cis-Trans Isomers
3) ENANTIOMERS (optical isomers)
What is a Constitutional/Structural Isomer?
A compound with the SAME molecular formula but different ARRANGEMENT of atoms
What is a Cis-Trans Isomer?
MUST HAVE A DOUBLE BOND, which can rotate. Each carbon in the double bond must have 2 DIFFERENT GROUPS attached.
What is a ENANTIOMER (optical isomer)?
Enantiomers are a pair of molecules that are MIRROR IMAGES of each other. They have the same atoms but they are arranged differently in 3D. They MUST have an ASYMMETRIC CARBON ATOM (a carbon bonded to 4 different groups). We call this a CHIRAL carbon.
What is a CHIRAL Carbon?
A carbon bonded to 4 different groups
Optical Isomers have the SAME physical properties (m.p & b.p) and chemical properties except for ONE, what is it?
“They will rotate to plane-polarized light in equal but opposite directions.”
The Isomer that involves COOH, C, H, NH₂ and R are always shown as ______________. DO NOT draw any bonds at right angles that will be a Not Achieved, show them at _____________ than 90° apart.
TETRAHEDRAL
GREATER
Many enzymes and amino acids have __________ CARBONS so they can have ___________ ISOMERS OF THEMSELVES.
CHIRAL
OPTICAL
What does ‘Chiral’ mean?
A molecule that cannot be rotated/superimposed on each other.
What does ‘AChiral’ mean?
A carbon that does not have chirality/molecule.
What does ‘S isomer’ mean?
Left hand isomer
What does ‘R isomer’ mean?
Right hand isomer
What is an equal mixture of both isomers called?
A RESEMIC MIXTURE.
Haloalkanes contain halogens from group ___?
17
What are Haloalkanes classified as?
1°, 2° or 3° depending on the number of CARBONS bonded to the carbon atom attached to the halogen.
In a substitution reaction the halogen functional group is replaced with various ‘_______’.
GROUPS
In an elimination reaction HX (X is a halogen) is ____________ from the molecule and a ______ bond is formed. HOT CONCENTRATED ______________ KOH is required. The product formed is an __________.
REMOVED
DOUBLE
ALCOHOLIC
ALKENE
What is Saytzeff’s Elimination Rule?
“If there is a CHOICE of C atoms from which the H can be removed to produce 2 different products, then the MAJOR product will be the one formed when the H ATOM IS REMOVED from the C with the LEAST number of H atoms.”
For the major product: ‘The POOR GET POORER’. (But don’t say that in exam).
What is the test for an Haloalkane?
Will it float on water, yes or no?
What is the suffix for an Alcohol?
-ol
What is the attachment group for an alcohol?
OH
What can Alcohols be classified as?
Primary (1°)
Secondary (2°)
Tertiary (3°)
What is a Primary (1°) alcohol?
The C holding the OH group is itself attached to no other (or 1 other) C.
What is a Secondary (2°) alcohol?
The C holding the OH group is itself attached to 2 other C.
What is a Tertiary (3°) alcohol?
The C holding the OH group is itself attached to 3 other C.
How can you make an alcohol?
By reacting haloalkanes with NaOH₍ₐ𝓆₎ or KOH₍ₐ𝓆₎
How do you turn an ALKENE into an ALCOHOL?
By using DILUTE ACID
How can DILUTE ACID be shown in symbols?
H₂O/H⁺ or written as dil. H₂SO₄
How do ALCOHOLS undergo Elimination reactions?
With WARM CONCENTRATED H₂SO₄
What is CONCENTRATED H₂SO₄?
A dehydrating agent that removes WATER (h-OH) from an alcohol.