ypes of Reactions, Heterolytic Mechanisms, Nucleophiles and Electrophiles, and Energies of Organic Reactions

Question 1

What is an addition reaction?

Answer 1

Two reactants combining to form a single product

Question 2

What is the result of an addition reaction?

Answer 2

Decrease in the # of pi bonds, increase in the # of sigma bonds

Question 3

What is an elimination reaction?

Answer 3

Single reactant splits into two products

Question 4

What is the result of an elimination reaction?

Answer 4

Increase in the # of pi bonds, Decrease in the # of sigma bonds

Question 5

What is a substitution reaction?

Answer 5

Two reactants exchanging parts to form two new products

Question 6

What is the result of an substitution reaction?

Answer 6

No change in the # of pi bonds but groups were exchanged

Question 7

What is a Rearrangement reaction?

Answer 7

Single reactant yielding a constitutional isomer as product

Question 8

What is the result of a rearrangement reaction?

Answer 8

No change in the # of pi bonds but groups, bonds and atoms were reorganized

Question 9

What is a heterolytic mechanism?

Answer 9

Unsymmetrical breaking and making of bonds

Question 10

What is an unsymmetrical bond breaking?

Answer 10

Two bonding electrons remain with one product fragment, leaving the other with a vacant orbital after bond breaking

Question 11

What are nucleophiles?

Answer 11

Electron rich species that donate electron pairs to electrophiles in a polar bond forming reaction; lewis base

Question 12

What are electrophiles?

Answer 12

Substances that accept electron pairs from a nucleophile; lewis acid

Question 13

What are the rules writing organic molecules using curved arrow?

Answer 13

1. Electron moves from a nucleophilic source to an electrophilic sink
2. The octet rule should be followed when pushing electrons. This may cause formal charges

Question 14

What is gibbs free energy?

Answer 14

Change in energy that occur during a chemical reaction

Question 15

What happens when Delta G is <0

Answer 15

Reaction is exergonic; spontaneous

Question 16

What happens when Delta G is >0

Answer 16

Reaction is endergonic; non spontaneous

Question 17

Which side is favored if Delta G is < 0

Answer 17

Product

Question 18

Which side is favored if Delta G is > 0

Answer 18

Reactant

Question 19

What happens when a reaction is exothermic

Answer 19

Heat is released; Delta H < 1

Question 20

What happens when a reaction is endothermic

Answer 20

Heat is absorbed; Delta H > 1

Question 21

What happens when Delta S > 1

Answer 21

Entropy increase; more disordered system

Question 22

What happens when Delta S < 1

Answer 22

Entropy decrease; Less disordered system

Question 23

What does the number of hills in an energy diagram indicate?

Answer 23

The number of steps in a reaction

Question 24

What does the steepness/height of the hill in an energy diagram indicate?

Answer 24

Rate of reaction

Question 25

Compare a “tall” hill and a “short” hill

Answer 25

Tall hill has a slower reaction rate than short hill

Question 26

What is a transition state?

Answer 26

The point at which the compound is in the process of transformation

Question 27

Where is the transition state located on an energy diagram

Answer 27

Top of the hill

Question 28

What is activation energy?

Answer 28

Energy required to go from reactant to transition state

Question 29

What is a reaction intermediate?

Answer 29

Species that are neither reactant nor the final product