Chemical Reactivity and Mechanisms Flashcards
Is bond cleavage endo or exo?
endo (requires energy)
What is homolytic cleavage?
When bond breaks evenly, each side leaving with one electron
What is heterolytic cleavage?
When bond breaks unevenly, leaving one side with both bond electrons and the other with an empty orbital
What is the process that causes heterolytic cleavage?
Heterolysis
What is a positively charged carbon called?
Carbocation
What is electrophile
Electron lover
Accepts a pair of electrons to form a new covalent bond
What is nucleophile
Nucleus lover
Donates a pair of electrons to form a new covalent bond
What causes homolytic cleavage?
homolysis
What is produced from homolytic cleavage?
fragments with radicals (unpaired electrons)
What is the energy required to homolytically cleave a covalent bond?
bond dissociation energy (BDE)
T or F: BDE = Change in enthalpy?
T
What does the sign (+/-) of enthalpy reflect about the reaction?
-∆H : exothermic
+∆H : endothermic
How does bond length relate to bond strength?
Greater bond length = stronger bone
What is the difference between homolytic and heterolytic cleavage?
Homolytic: each fragment ends up w 1 electron
Heterolytic: one fragment ends up w both electron pairs
What type of cleavage is BDE defined by?
Homolytic cleavage (defined in terms of radicals)
