Term
| As carbons are added in a single chain and the molecular weight is increases, the intermolecular forces what |
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Definition
also increase and therefore, boiling point increases
branching however, tends to decrease boiling points |
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Term
| when density increases, what also increases |
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Definition
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Term
| what are alkanes soluble in |
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Definition
| benzene, chloroform, carbon tetrachloride, and other hydrocarbons |
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Term
| melting point is not only maliable to molecular weight, but as the branching of a structure increases what happens |
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Definition
| the melting point increases |
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Term
| what is the ring strain for cyclohexane |
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Definition
| ring strain for cyclohexane is zero |
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Term
| what does lower ring strain mean in terms of stability |
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Definition
| the lower the ring strain, the lower the energy and the higher the stability of the structure |
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Term
| at room temperature, there are several conformers of a single molecule, which is the most predominate |
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Definition
| the conformer that maintains the lowest energy- therefore, the most stable structure |
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Term
| why do most substituents favor equatorial positioning over axial |
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Definition
crowding often occurs in axial positioning, which puts strain on the molecule, thus increasing the overall energy of the structure-causeing it to be less stable
sustituents favor equatorial |
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Term
| cis-isomers of a cyclohexane structure elevate the molecules energy level because |
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Definition
| they increase the steric hindrence of the molecule |
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Term
| when alkanes are introduced to oxygen and a flame, what happens |
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Definition
carbon dioxide and water are formed and so is heat
once this reaction begins it is self-perpetuating, because it gives off more heat |
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Term
| how does heat of combustion compare to energy level and stability of a molecular structure |
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Definition
| the higher the heat of combustion, the higher the energy level and therefore, the less stable the molecular structure |
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Term
| what are the three steps in halogenation of a alkane |
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Definition
initiation: a aiatomic halogen is split by heat of UV light
propagation: the halogen radical removes a hydrogen from the alkane to form a alkyl radical. then the alkyl radical can bind to a halogen to form a alkyl halide
termination: either two radicals bond together |
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Term
| in halogenation of an alkane, what is order of stability |
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Definition
| tertiary, secondary, primary and methyl |
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Term
| are pi bonds more or less stable than sigma bonds |
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Definition
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Term
to synthesis alkenes, alkanes with one or two function groups will be dehydrated to form a double bond
what types of reagents/solvents would you use, and discuss the rule in which elimination follows |
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Definition
one would use a strong acid only an alcohol functional group and heat, lots of heat
this would follow an E1 mechanism and therefore, form a carbocation
carbocation stability follows 3, 2, 1, methyl
saytzeff rule bitch |
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Term
| can dehydrohalogenation undergo two mechanisms |
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Definition
yes, it can undergo an E 1 mechanism (without a strong base-halogen pops off) and an E 2 mechanism (this is with a strong base)
If the base is too bulky it violates the saytzeff rule- LDA |
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Term
| how can you measure the relative stability of alkenes |
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Definition
test the heats of hydrogenation, the higher the heat, the more stable the alkene
this is an example of the mechanism catalytic hydrogenation |
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Term
| what do alkynes produce when they undergo ozonolysis |
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Definition
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Term
| describe how alkenes and electrophiles are relevent together |
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Definition
an alkene's double bond is an electron-rich area that loves electrophiles
An electrophile is any positive charged proton, even if it is a temporary partially positively charged particle of a dipole moment
they love each other |
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Term
| which are the most reactive alkenes towards electrophilic addition |
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Definition
| the most thermodynamically stable alkenes- ie, tetra-substituted alkenes |
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Term
context: you have an alkene, and you want to form two different alcohol molecules, one that rearranges and one that doesn't rearrange
what do you do |
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Definition
one, use dilute acid and low temperatures
two, use oxymercuration |
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Term
context: you have an alkene and you want to form an alcohol, but anti markovinkov's
how |
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Definition
hydroboration
bh3, h2o2, oh- |
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Term
| what is the difference between alkenes and alkanes and how they react with halogens |
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Definition
alkanes need heat or UV light to break the halogens homolytically
alkenes will form a bromonium ion first |
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Term
| does benzene undergo subsitution or addition |
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Definition
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Term
| what do electron withdrawing groups do to substituents |
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Definition
| they are deactivating and therefore, direct substituents to the meta position |
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Term
| what do electron donating groups do |
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Definition
| they activate the ring and therefore, direct substituents to the ortho and para position |
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Term
| what are halogens considered to be in regards to benzene substition |
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Definition
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Term
| who is more acidic, alkanes or alkenes |
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Definition
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Term
| in an SN1 reaction, the rate of the reaction is directly proportional to |
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Definition
| the concentration of substrate (this is the electrophile being attacked by the nucleophile), not the nucleophile |
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Term
| what is the obvious difference between SN1 and SN2 reactions |
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Definition
| SN1 reactions have carbocations |
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Term
| in an SN2 reaction, the rate is dependent on what |
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Definition
| the concetration of the substrate and the nucleophile |
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Term
| why dont SN2 reactions typically occur with tertiary structures |
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Definition
| too much steric hindrance |
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Term
| what is the best nucleophile for SN2 reactions |
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Definition
| the most electronegative atoms |
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Term
| what kind of solvents would you use for SN1 reactions and SN2 reactions |
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Definition
SN1-polar protic solvents will increase the rate because it stablizes the carbocation
SN2- polar aprotic solvents because they wont form hydrogen bonds |
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Term
| what are the five S's concerning nucelophiles |
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Definition
| substrate, solvent, speed, stereochemistry & skelton arrangement |
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Term
| when do SN2 reactions occur |
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Definition
| when they are not sterically hindered, thus: methyl, primary and secondary arrangements |
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Term
| what does a highly polarized solvent do to SN1 and SN2 reactions |
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Definition
highly polar solvent will increase the rate of the SN1 reaction by stabilizing the carbocation
but, decrease the rate of SN2 |
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Term
| SN1 reactions create what in terms of compounds |
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Definition
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Term
| why do alcohols have a higher boiling point than alkanes |
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Definition
| the capability of hydrogen bonding increase the intermolecular forces, thus increasing its boiling point |
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Term
| what is the order of acidity for alcohols from strongest to weakest |
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Definition
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Term
| how does a grignard synthesis work |
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Definition
| when carbon is bonded to a metal, it takes on a slighty negative charge since it is more elctronegative than the metal. This makes is a nucleophile and base. This nucleophile will attack a carbonly group |
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Term
| context: you have a vicinal diol, and you place it in hot sulfuric acid, what happens |
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Definition
| you'd expect it to form elimination, but instead it forms a single carbonyl group |
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Term
| how do ether's boiling points compare to alkanes |
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Definition
| roughly comparable when molecular weights are similar |
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Term
| what happens when an ether is mixed with a halo-acid (HI) |
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Definition
| it forms an alcohol and alkyl halide |
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