ypes of Reactions, Heterolytic Mechanisms, Nucleophiles and Electrophiles, and Energies of Organic Reactions Flashcards
What is an addition reaction?
Two reactants combining to form a single product
What is the result of an addition reaction?
Decrease in the # of pi bonds, increase in the # of sigma bonds
What is an elimination reaction?
Single reactant splits into two products
What is the result of an elimination reaction?
Increase in the # of pi bonds, Decrease in the # of sigma bonds
What is a substitution reaction?
Two reactants exchanging parts to form two new products
What is the result of an substitution reaction?
No change in the # of pi bonds but groups were exchanged
What is a Rearrangement reaction?
Single reactant yielding a constitutional isomer as product
What is the result of a rearrangement reaction?
No change in the # of pi bonds but groups, bonds and atoms were reorganized
What is a heterolytic mechanism?
Unsymmetrical breaking and making of bonds
What is an unsymmetrical bond breaking?
Two bonding electrons remain with one product fragment, leaving the other with a vacant orbital after bond breaking
What are nucleophiles?
Electron rich species that donate electron pairs to electrophiles in a polar bond forming reaction; lewis base
What are electrophiles?
Substances that accept electron pairs from a nucleophile; lewis acid
What are the rules writing organic molecules using curved arrow?
- Electron moves from a nucleophilic source to an electrophilic sink
- The octet rule should be followed when pushing electrons. This may cause formal charges
What is gibbs free energy?
Change in energy that occur during a chemical reaction
What happens when Delta G is <0
Reaction is exergonic; spontaneous
What happens when Delta G is >0
Reaction is endergonic; non spontaneous
Which side is favored if Delta G is < 0
Product
Which side is favored if Delta G is > 0
Reactant
What happens when a reaction is exothermic
Heat is released; Delta H < 1
What happens when a reaction is endothermic
Heat is absorbed; Delta H > 1
What happens when Delta S > 1
Entropy increase; more disordered system
What happens when Delta S < 1
Entropy decrease; Less disordered system
What does the number of hills in an energy diagram indicate?
The number of steps in a reaction
What does the steepness/height of the hill in an energy diagram indicate?
Rate of reaction
