Organic Reactions Flashcards
What does an acid-base reaction form?
Conjugate acid and conjugate base
What is required of the reactants for an acid-base reaction to run?
Reactants are stronger than the products
What is the definition of a lewis acid?
Electron acceptor, electrophile
Is a lewis acid an electrophile or nucleophile?
Electrophile
Is a lewis base an electrophile or nucleophile?
Nucleophile
What is the definition of a lewis base?
Electron donor, nucleophile
Is an electron donor a lewis acid or base?
Base
Is an electron acceptor a lewis acid or base?
Acid
What is a coordinate covalent bond?
Bond in which both bonding e- come from the same atom
What is the definition of a Bronsted-Lowry acid?
H+ donor
What is the definition of a Bronsted-Lowry base?
H+ acceptor
Is a proton acceptor a Bronsted-Lowry acid or base?
Base
Is a proton donor a Bronsted-Lowry acid or base?
Acid
What is the definition of an amphoteric molecule?
Can act as a Bronsted-Lowry acid or base depending on the solution
Is water an acid or base in a basic solution and what product is formed?
Acid, donates H+ to make OH-
Is water an acid or base in an acidic solution and what product is formed?
Base, accepts H+ to make H3O+
What are some examples of amphoteric molecules?
H2O
AL(OH)3
HCO3-
HSO4-
What is Ka and how is it calculated?
Acid Dissociation Constant, represents the strength of an acid
Ka=([H+][A-])/[HA]
pKa
-log(Ka)
Does a smaller Ka indicate a stronger or weaker acid?
Stronger
What pKa defines a strong acid?
Lower,
What does it mean if an acid is strong?
Dissociates in aqueous solution
Does acidity increase or decrease as you go down the periodic table?
Increase
Does acidity increase or decrease as you go up the periodic table?
Decrease
Does acidity increase or decrease with electronegativity?
Increase
Which hydrogen is easily lost in a carbonyl compound?
Alpha hydrogen (bonded to the alpha carbon, which is next to the carbonyl group)
Is electro and nucleophilicity a thermodynamic or kinetic property?
Kinetic property based on reaction rates
What is a kinetic property based on?
Reaction rates
What is a thermodynamic property based on?
Reaction equilibrium
Is acid-base strength a thermodynamic or kinetic property?
Thermodynamic based on acid-base equilibrium
What are nucleophiles?
“nucleus loving” with lone pairs or pi bonds that can form new bonds
Is nucleophilicity similar to acidity or basicity?
Basicity
Are nucelophiles usually positive or negative?
Negative
Do electronegative atoms increase or decrease nucleophilicity?
Decrease because they are electron withdrawing (reduce negative charge)
Do bulky groups increase or decrease nucleophilicity?
Decrease because they provide steric hindrance
Rank the following in decreasing reactivity: Ester Amide Anhydride Carboxylic Acid
Anhydride>Carboxylic Acid/ Ester > Amide
Do protic solvents increase or decrease nucleophilicity?
Decrease by protonating the nucleophile
What are electrophiles?
“Electron-loving” species with a positive charge or positively polarized atom that acts as an electron acceptor
Do electrophiles behave like acids or bases?
Acids
Heterolytic Reactions
When a bond is broken and both electrons go to the same atom
Are weak bases good or bad leaving groups?
Good
Why are weak bases good leaving groups?
They are stable with extra electrons
How many steps is an Sn1 reaction?
Two
What are the step(s) of an Sn1 reaction?
- Leaving group leaves and generates a carbocation
2. Nucleophile attacks the carbocation
What is the stereochemistry of the products of an Sn1 reaction?
Usually racemic
What reaction order is an Sn1 reaction?
First order
Which step is rate-limiting in an Sn1 reaction?
First step
What type of compounds are best suited for Sn1 reactions?
Bulky, more substituted alkanes
How many steps is an Sn2 reaction?
One
What are the step(s) of an Sn2 reaction?
- Back-side attack by nucleophile at the same time the leaving group leaves
What is the stereochemistry of the products of an Sn2 reaction?
Inverted compared to the original
What reaction order is an Sn2 reaction?
Second order
What type of compounds are best suited for an Sn2 reaction?
Strong nucleophiles and alkanes without steric hindrance
What happens in redox reactions?
The oxidation states of the reactants change