Module 4: Alkenes Flashcards
Define sigma bond
A bond formed by the lengthways overlap of orbitals directly between two bonding atoms.
Define Pi bond
A type of covalent bond formed when adjacent p-orbitals overlap sideways above and below the bonding c atoms.
What does the carbon-carbon double bond mean?
A bond formed between two carbon atoms that share two pairs of electrons.
Define structural isomerism.
Molecules with the same molecular formula but different structural arrangements of atoms.
What is stereoisomerism?
Molecules with the same structural formula but different arrangements of atoms in space.
What is one type of stereoisomerism?
Geometric isomerism.
When does stereoisomerism occur?
As a result of restricted rotation about the C=C double bond.
What is a cis isomer?
An isomer with the same groups on the same side.
What is a trans isomer?
An isomer with the same groups on either side.
What is the priority group?
The atom with the highest atomic number.
When are cis-trans isomers relevant?
When there are at least two of the same groups present.
Name the four types of reactions of alkenes.
- Hydrogenation
- Hydration
- Halogenation (water)
- Addition of an acid
Fill in the blank: The carbon-carbon double bond is represented as _______.
C=C
What is electrophilic addition?
A reaction where an electrophile reacts with a nucleophile to form a product
Electrophilic addition typically occurs with alkenes and alkynes.
What is an electrophile?
A species that accepts an electron pair
Electrophiles are often positively charged or neutral molecules with vacant orbitals.
What does the term āC=Cā signify?
A double bond between two carbon atoms
This notation indicates a pi bond and sigma bond between the two carbons.
Explain electrophilic addition in alkenes.
Addition of electrophiles to the double bond of alkenes to form saturated products
This process results in the breaking of the C=C bond.
What are the products formed in electrophilic addition reactions?
Saturated products
The reaction converts unsaturated hydrocarbons to saturated hydrocarbons.
What attracts electrophiles to a double bond?
The high electron density of the double bond
The electron-rich area of the double bond interacts with electrophiles.
Fill in the blank: Electrophiles have an atom with _______ charge.
positive
What happens to the C=C bond during electrophilic addition?
It breaks to form a new single bond
This allows for the addition of new atoms or groups to the molecule.
What is a carbocation?
A positively charged carbon ion
Carbocations are key intermediates in many organic reactions, including electrophilic additions.
How does a nucleophile interact with an electrophile in electrophilic addition?
The nucleophile donates a pair of electrons to the electrophile
This interaction forms new bonds and stabilizes the reaction intermediate.
