6-Understanding Organic Reactions Flashcards
Vocab:
Reaction in which an atom or a group of atoms is REPLACED by another atoms or a group of atoms
Substitution
Vocab:
Reaction in which elements of the starting material are “lost” and a PI BOND is FORMED.
Elimination
Vocab:
Reaction in which elements are ADDED to a starting material
Addition
Reaction in which one SIGMA bond BREAKS and another one FORMS at the SAME carbon atom
Substitution reaction
Reaction in which TWO SIGMA bonds are BROKEN and a PI bond is FORMED between adjacent atoms
Elimination reaction
Reaction in which a PI bond is BROKEN and TWO SIGMA bonds are formed
Addition reaction
Vocab:
Breaking a bond by equally dividing the electrons between two atoms
Homolysis
Vocab:
Breaking a bond by UNEQUALLY dividing two atoms in a bond. Electrons normally end up on the more electronegative atom
Heterolysis
Vocab:
A reactive intermediate with a SINGLE UNPAIRED ELECTRON that is highly unstable
Radical
Vocab:
A POSITIVELY charged Arvin generate by giving two electrons to Z and none to C
Carbocation
Vocab:
A NEGATIVELY charged carbon generated by giving two electro d to C and none to Z
Carbanion
Nucleophile or electrophile?
Radical?
Electrophile
Nucleophile or electrophile?
Carbocation
Electrophile
Nucleophile or electrophile?
Carbanion
Nucleophile
Bond formation always ____ energy
Releases
positive or negative delta-H?
Energy is absorbed
Positive
POSITIVE or NEGATIVE delta-H?
Endothermic
Positive
POSITIVE or NEGATIVE delta-H?
Energy is released
Negative
POSITIVE or NEGATIVE delta-H?
Exothermic
Negative
Vocab:
Enthalpy change or HEAT of a reaction
Delta-H
Endothermic or exothermic?
Energy is ABSORBED
Endothermic
Endothermic or exothermic?
Energy is RELEASED
Exothermic
Endothermic or exothermic?
BOND DISSOCIATION ENERGY
Delta-H always positive -> Endothermic
Endothermic or exothermic?
Bond FORMATION
Always negative -> exothermic
The STRONGER the BOND, the (HIGHER/LOWER) the BOND DISSOCIATION ENERGY
Higher
BOND DISSOCIATION ENERGY (INCREASES/DECREASES) (UP/DOWN A COLUMN or LEFT/RIGHT ACROSS A ROW)
Bond dissociation energy DECREASES DOWN A COLUMN of the periodic table
Which is STRONGER? Bonds BROKEN in STARTING MATERIALS or bonds FORMED in PRODUCTS?
Positive delta-H
Bonds BROKEN in STARTING MATERIALS are stronger
Which is STRONGER? Bonds BROKEN in STARTING MATERIALS or bonds FORMED in PRODUCTS?
Negative delta-H
Bonds FORMED in PRODUCTS
Reactant or product favored?
Keq > 1
Product
Reactant or product favored?
Keq < 1
Reactant
Keq (</>) 1
Product favored
Keq > 1
Keq (</>) 1
reactant favored
Keq < 1
Positive/Negative delta-G
Keq > 1
negative
Positive/Negative delta-G
Keq < 1
positive
Product/Reactant favored?
Positive delta-G
reactant
Product/Reactant favored?
Negative dela-G
product
Product/Reactant favored?
Energy of products is LOWER than the energy of the reactants
product
Product/Reactant favored?
Energy of the products is HIGHER than the energy of the reactants
reactant
Equilibrium favors (more/less) stable
more stable
Equilibrium favors (lower/higher) in energy
lower
Reactions resulting in a(n) (increase/decrease) in delta-S is favored
increase
delta-S is?
entropy
Product/Reactant favored?
Negative delta-H
product
Product/Reactant favored?
Positive delta-H
reactant
delta-H is negative or positive?
product favored
negative
delta-H is negative or positive?
reactant favored
positive
delta-H is negative or positive?
bonds in the product are STRONGER than the bonds in the reactants
negative
delta-H is negative or positive?
bonds in the reactants are STRONGER than the bonds in the products
product
LARGER Ea (slower/faster) reaction
slower
FAST reaction has a lower/higher Ea
lower
HIGH concentration = (slower/faster) reaction
faster
HIGHER temperature = (slower/faster reaction)
faster
Fast reactions have (small/large) rate constants
large
Slow reactions have (small/large) rate constants
small
A rate equation contains ____ involved in a ONE-STEP mechanism
ALL reactants
A rate equation contains ____ involved in a MULTISTEP mechanism
ONLY the reactants involved in the RATE-DETERMINING step
A catalyst (slows down/speeds up) a reaction
speeds up
Does a catalyst appear in the products?
No
delta-S positive/negative?
products are MORE disordered than reactants
positive
