Term
| types of organic reactions |
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Definition
-addition
-elimination
-substitution
-rearrangement |
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Term
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Definition
occur when 2 reactants add to form one product, with no atoms left over
A + B --> AB |
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Term
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Definition
occur when a single reactant splits into 2 products
AB --> A + B |
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Term
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Definition
occur when 2 reactants exchange parts to yield 2 new products
AB + CD --> AD + CB |
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Term
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Definition
occur when a single product undergoes a rearrangement of bonds to yield an isomeric product
ABCD --> DBCA |
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Term
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Definition
| describes the bonds broken and formed in a chemical reaction, and accounts for all reactants and products |
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Term
| types of bond breaking in chemical reactions |
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Definition
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Term
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Definition
| symmetrical bond breakinbg such that 1 electron remains with each fragment |
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Term
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Definition
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Term
| heterolytic bond breaking |
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Definition
| unsymmetrical bond breaking such that both electrons remain with one fragment and the other fragment has a vacant orbital |
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Term
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Definition
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Term
| types of bond formation in chemical reactions |
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Definition
-symmetrical
-unsymmetrical |
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Term
| symmetrical bond formation |
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Definition
| each reactant contributes 1 electron to a covalent bond |
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Term
| depiction of symmetrical bond formation |
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Definition
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Term
| unsymmetrical bond formation |
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Definition
| both electrons in a covalent bond come from 1 reactant |
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Term
| depiction of unsymmetrical bond formation |
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Definition
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Term
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Definition
-radical
-polar
-pericyclic |
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Term
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Definition
| involve symmetrical bond breaking and bond formation |
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Term
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Definition
| involve unsymmetrical bond breaking and bond formation |
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Term
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Definition
| reactant that contains an atom with an unpaired electron |
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Term
| why radicals are highly reactive |
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Definition
| because they contain an atom with an unpaired electron |
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Term
| substitution reaction that involves a radical |
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Definition
| occurs when a radical abstracts an atom and a bonding electron from another molecule |
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Term
| addition reaction that involves a radical |
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Definition
| occurs when a radical adds to a double bond |
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Term
| steps in a radical reaction |
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Definition
-initiation step
-propagation steps
-termination step |
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Term
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Definition
| produces radicals by the symmetrical clevage of a bond |
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Term
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Definition
| chain reaction where a radical abstracts an atom to produce a new radical and a stable molecule |
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Term
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Definition
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Term
| how bond breaking and formation works in radical reactions |
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Definition
| all bonds are formed and broken by reactions of species with odd numbers of electrons |
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Term
| some characteristics of polar reactions |
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Definition
-they occur as a result of differences in bond polarities within molecules
-electron-rich sites in 1 molecule react with electron-poor sites in another molecule
-the movement of electron pairs is shown by curved, fullheaded arrows
-the reacting species are nucleophiles and electrophiles
-many polar reactions can be explained in terms of acid-base reactions |
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Term
| polar reactions occur as a result of... |
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Definition
| differences in bond polarities within molecules |
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Term
| the polarities within polar molecules are usually due to... |
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Definition
| electronegativity differences between atoms |
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Term
| electronegativity differences may also be due to... |
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Definition
-interactions of functional groups with solvents
-interactions of functional groups with Lewis acids or bases |
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Term
| if there's no real electronegativity difference between atoms in a molecule, how can that bond behave as a polar bond? |
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Definition
| some bonds in which 1 atom is polarizeable may also behave as polar bonds |
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Term
| the sites that react in polar reactions |
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Definition
| the electron-rich sites in one molecule react with the electron-poor sites in another molecule |
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Term
| the movement of an electron pair in a polar reaction is shown by... |
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Definition
| a curved, fullheaded arrow |
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Term
| the reacting spevcies in a polar reaction |
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Definition
-nucleophile
-electrophile
-some compounds behave as both nucleophiles and electrophiles |
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Term
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Definition
| compound with electron-rich atom |
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Term
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Definition
| compound with electron-poor atom |
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Term
| many polar reactions can be explained in terms of... |
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Definition
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Term
| an example of a polar reaction |
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Definition
| addition of HBr to ethylene |
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Term
| what type of addition is the addition of HBr to ethylene? |
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Definition
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Term
| the behavior of the π electrons in ethylene in the addition of HBr to ethylene |
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Definition
| the π electrons in ethylene behave as a nucleophile |
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Term
| how the reaction of the addition of HBr to ethylene begins |
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Definition
| the attack of the π electrons on the electrophile H+ |
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Term
| what happens at the end of the reaction of the addition of HBr to ethylene? |
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Definition
| the resulting intermediate carbocation reacts with Br- to form bromoethana |
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Term
| rules for using curved arrows in polar reaction mechanisms |
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Definition
-electrons must move from nucleophile to electrophile
-nucleophile can be negative or neutral
-electrophile can be positive or neutral
-the octet rule must be followed |
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Term
| how chemical reactions can be expressed as equilibria |
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Definition
| all chemical reactions are equilibria that can be expressed by an equilibrium constant (Keq) that shows the ratio of products to reactants |
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Term
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Definition
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Term
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Definition
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Term
| what must the energy be for the reaction to proceed as written? |
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Definition
| to proceed as written, the energy of the products must be lower than the energy of the reactants |
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Term
| the energy change that occurs during a reaction is described by... |
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Definition
| ΔG°, the Gibbs free-energy change |
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Term
| favorable reaction (spontaneous) |
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Definition
| have negative ΔG° and are exothermic |
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Term
| unfavorable reaction (nonspontaneous) |
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Definition
| have positive ΔG° and are endothermic |
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Term
| the relationship between ΔG° and Keq |
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Definition
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Term
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Definition
| enthalpy, which is a measure of the total change in bonding energy during a reaction |
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Term
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Definition
| the reaction is exothermic |
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Term
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Definition
| the reaction is endothermic |
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Term
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Definition
| entropy, which is a measure of the freedom of motion of a reaction |
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Term
| rxn with positive entropy |
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Definition
| produces 2 product molecules from 1 reactant molecule |
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Term
| rxn with negative entropy |
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Definition
| produces 1 product molecule from 2 reactant molecules |
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Term
| relationship between ΔG°, ΔH°, and ΔS° |
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Definition
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Term
| bond dissociation energy (D) |
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Definition
| measures the heat needed to break a bond to produce 2 radical fragments |
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Term
| what happens to the strength of bonds in exothermic reactions? |
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Definition
| the bonds formed are stronger than the bonds broken |
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Term
| what reaction energy diagrams show |
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Definition
| the energy changes that occur during a reaction |
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Term
| how a reaction energy diagram is set up |
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Definition
| vertical axis represents energy changes and horizontal axis represents the progress of the reaction |
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Term
| the highest energy species in a reaction |
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Definition
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Term
| can a reaction have more than 1 transition state? |
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Definition
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Term
| the energy of activation (ΔG‡) |
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Definition
| the difference in energy between the reactants and the transition state |
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Term
| values of ΔG‡ range from... |
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Definition
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Term
| what a reaction can do after reaching the transition state |
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Definition
| it can go on to form products or revert to starting material |
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Term
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Definition
| in a reaction of at least 2 steps, this is the species that lies at the energy minimum between 2 transition states |
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Term
| energy of an intermediate |
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Definition
| even though it lies between 2 transition states, it is a highg energy species |
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Term
| can an intertmediate be isolated? |
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Definition
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Term
| the solvents laboratory reactions are carried out in |
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Definition
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Term
| the medium biological reactions occur in |
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Definition
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Term
| the temperatures laboratory reactions take place in |
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Definition
| a wide range of temperatures |
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Term
| the temperatures biological reactions take place in |
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Definition
| the temperature of the organism, usually within narrow limits |
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Term
| the catalyzing in laboratory reactions |
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Definition
| uncatalyzed or use simple catalysts |
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Term
| the catalyzing in biological reactions |
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Definition
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Term
| description of laboratory reagents |
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Definition
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Term
| description of biological reagents |
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Definition
| involve large, complex coenzymes |
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Term
| specificity of biological reactions |
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Definition
| they have high specificity for substrate |
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Term
| specificity of laboratory reactions |
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Definition
| they are relatively nonspecific |
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Term
| are atoms w/ vacant orbitals electrophiles or nucleophiles? |
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Definition
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Term
| a type of rxn that has a carbocation intermediate |
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Definition
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Term
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Definition
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Term
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Definition
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Term
| activation energy vs. speed of rxn |
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Definition
| the higher the activation energy, the slower the rxn |
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Term
| are pi bonds electrophiles or nucleophiles? |
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Definition
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Term
| are aromatic rings electrophiles or nucleophiles? |
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Definition
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Term
| the difference between exothermic and exergonic |
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Definition
exothermic = -ΔH°
exergonic = -ΔG° |
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Term
| the difference between endothermic and endergonic |
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Definition
endothermic = +ΔH°
endergonic = +ΔG° |
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Term
| location of transition state in energy diagram |
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Definition
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Term
| location of intermediate in energy diagram |
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Definition
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