Chapter 3 - Alkenes and Alkynes Flashcards
What type of hydrocarbons are alkenes and alkynes?
Unsaturated
General formula for alkenes
CnH2n
General formula for alkynes
CnH2n-2
General formula for saturated hydrocarbon
CnH2n+2
Alkadienes that are separated by one C-C single bond
Conjugated
Alkadienes that are separated by more than one C-C single bond)
Nonconjugated
True or False:
carbon–carbon double bonds are longer than carbon–carbon single bonds
False
(Shorter)
bond is formed from the end-on overlap of two orbitals
Sigma
bond is formed by lateral overlap of p orbitals on adjacent atoms
Pi
Reaction that is common for alkanes
Substitution
Reaction common for alkenes
Alkenes
True or False:
sigma bonds are usually stronger than pi bonds
True
Test for unsaturation
Bromine test
Water adds as H-OH in hydration and the products are what?
Alcohols
It gives only one of the two possible regioisomers
Regiospecific
It produces mainly one regioisomer
Regioselective
The only product for regiospecific
2-propanol
electron-poor reactants; they seek electrons.
Electrophiles
electron-rich reactants; they form bonds by donating electrons to electrophiles.
Nucleophiles
act as a supplier of pi electrons to an electron-seeking reagent
Double bond
A positively charged carbon atom bonded to three other atoms
Carbocation
What rule is this?
The electrophilic addition of an unsymmetric reagent to an unsymmetric double bond proceeds in such a way as to involve the most stable carbocation.
Markovnikov’s rule
It shows the changes in energy that occur in the course of a reaction
Reaction energy diagram
A structure with maximum energy for a particular reaction step
Transition state
It is the difference in energy between reactants and the transition state and determines the reaction rate.
Activation energy
True or False:
Higher the energy barrier, the faster the reaction
False
(Higher the energy barrier, the slower the reaction)
Addition of H-B to an alkene
Hydroboration
Addition of hydrogen to alkenes in the presence of a catalyst
Hydrogenation
Carbocation with a carbon–carbon double bond that is adjacent to the positively charged carbon atom
Allylic cation
the cycloaddition reaction of a conjugated diene and a dienophile to give a cyclic product in which three bonds are converted to two bonds and a new bond.
Diels-Alder reaction
True or False:
Alkenes react rapidly and quantitatively with ozone
True
It can be used to locate the position of a double bond.
Ozonolysis
Angle betweem teo sp orbitals of a triple bond
180 degrees
True or False
hydrogen atom on a triply bonded carbon is weakly basic
False
(Weakly acidic)
The process of polymer formation
Polymerization
