chemical reactions

what is an endothermic reaction?

reactants take in energy to form products; + △H

what is an exothermic reaction?

reactants release energy to form products; -△ H

what is homolytic cleavage ?

both sides of the bond get equal electrons during disassociation

what is heterolytic cleavage?

each side of the bond gets different amounts of electrons during disassociation

what is the relationship between entropy and disorder?

direct relationship; as entropy increases/decreases, disorder increases/decreases

what is the relationship between gas molecules and entropy?

direct relationship; as the amount of gas molecules increases/decreases, the entropy increases/decreases

Why do gas molecules increases entropy?

because the gas state contains molecules that are moving faster and are more spread out

what is the relationship between the state of molecules and entropy?

direct relationship; as the amount of molecules in the same state increases/decreases, the entropy increases/decreases

what is gibbs free energy?

the amount of energy available to do work; △G

what is an exergonic reaction?

no additional energy input required for a reaction; spontaneous; △G<0

what is an endergonic reaction?

additional energy input is required for a reaction; nonspontaneous; △G>0

When is △G spontaneous at all temps ?

When △H is - and △S is +

When is △G nonspontaneous at all temps ?

When △H is + and △S is -

When is △G spontaneous at low temps ?

When △H is - and △S is -

When is △G spontaneous at high temps ?

When △H is + and △S is +

What is △G when K_eq>1

△G<0

What is △G when K_eq<1

△G>0

what equation side is favored at equilibrium when K_eq>1

products

what equation side is favored at equilibrium when K_eq<1

reactants

what are kinetics used to discover in organic reactions?

the speed of a reaction

what is the relationship between rate constant (k) and reaction speed

direct relationship; as k increases/decreases, reaction speed increases/decreases

what is the relationship between reaction constant (k) and temperature

direct relationship; as temperature increases/decreases, k increases/decreases

what is the relationship between rate constant (k) and activation energy

inverse relationship; as activation energy increases/decreases, k decreases/increases

what does Hammond Postulate tell about a reaction

what the transition state looks like;

what does Hammond Postulate tell about an exothermic reaction

that the transition state look smore like the reactant

what does Hammond Postulate tell about an endothermic reaction

that the transition state looks more like the product

what does a catalyst do in a reaction

speeds up a reaction rate in the forward and reverse direction by lowering the activation energy with an alternative pathway/mechanism

how does a catalyst effect the shift of an equation during eqilibrium

no effect on equilibrium shift because it speeds up the forward AND reverse reaction

what is a nucleophile?

nucleus loving; “attacks” a electrophile; lewis base

what is an electrophile?

electron loving; is “attacked” by nucleophile; lewis acid

what makes a strong nucleophile?

atom bearing a negative charge

what makes a strong electrophile?

alkyl halides, carbocations, & carbonyls

what is the relationship between carbocation substitutions and stability

direct relationship; as carbocation substitutions increases/decreases, stability increases/decreases

what is the relationship between radical substitutions and stability

direct relationship; as radical substitutions increases/decreases, stability increases/decreases

what is the relationship between carbanion substitutions and stability

inverse relationship; as carbocation substitutions increases/decreases, stability decreases/increases