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140 Cards in this Set
- Front
- Back
- 3rd side (hint)
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How do you find the empirical formula of a molecule from the percent composition of its atoms? |
Take the percent composition and multiply them by 100 grams too see how many grams of each atom would be in a 100 gram sample. Divide this number by the atomic mass for each atom to get how many moles are in the sample. Divide the larges number of moles by the smallest and you have your ratio. |
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When does water boil?
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When its vapor pressure EQUALS the atmospheric pressure!
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Is there more or less atmospheric pressure at a high altitude? What effect does this have on boiling water?
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Less atmospheric pressure. It means that water boils at a lower temperature.
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What is the Aldol Reaction? What are the general reactants, mechanisms and products?
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It is a powerful way to make carbon-carbon bonds. You start with two aldehydes or ketones. In base: The h on one alpha carbon is removed (much more acidic than normal from resonance with O enolate ion) forming a carbanion. Enolate ion acts as a nucleophile to the carbonyl group of a second ald/ketone forming and O-, which will eventually be an OH group. Now you have the original ald. and a new alcohol.
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What is the Claisen condensation reaction? What are the general reactants, mechanisms and products?
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You start with a ketone and an ester. A hydrogen is removed from the alpha carbon of the ketone. This carbanion attacks the ester at the carbonyl carbon forming and O-. The electrons re-from a double bond and kick the alcohol portion of the ester off. This alcohol takes the other alpha hydrogen becoming a true alcohol and acid is applied to restore this H.
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What is an ionic equation?
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An equation that shows the molecules that are soluble in water as ions instead of molecules. Since they are strong electrolytes it's more realistic.
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What is a "spectator ion" and what is a NET ionic equation?
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Spectator ions are ions that do not participate in the reaction and exist as reactants and products in an ionic equation. a NET ionic equation is the ionic equation without spectator ions.
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What is a constitutional isomer?
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Isomers that differ in the order in which atoms are connected. They can be all scrambled, have different functional groups but still have the same molecular formula.
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What is a stereoisomer isomer?
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These isomers have the same functional groups and connectivities but differ in how the atoms are arranged in space. Ex sin vs anti, chair vs boat, R and S
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What is a geometric isomer?
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Differ in spatial position around a fixed-movement bond (double, triple or ring). Aka CIS-TRANS ISOMERS.
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What is a diastereomer?
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Stereoisomers that are NOT mirror images
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What is an enantiomer?
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Non-superimposable mirror image.
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What is a ylide? When is it used?
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A compound with two oppositely charged atoms next to each other in which both have octets. A Ph3P+C- is used in the Wittig reaction.
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What are the steps of the Wittig reaction?
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A ylide is formed from the triphenylphosphine nucleophile, an alkyl halide and a strong base making a positive and negative charge. A four membered ring is formed with a carbonyl as the positive is attacked by the O and he negative attacks the carbonyl carbon. The Ph3PO is removed, forming an alkene. The P-O double bond formation is the driving force for the reaction.
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The
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What is Clemmensen reduction? What are the reactants and the products?
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You take a benzyl ketone made via Friedel-Crafts and make it into an alkyl benzene. The reactants are the ketone and Zn(Hg) and strong acid (HCl). This is a difficult reactions and requires harsh conditions.
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What is Wolff-Kishner reduction?
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You take a benzyl ketone made via Friedel-Crafts and make it into an alkyl benzene. This is accomplished by using the ketone, NH2NH2 and strong base (KOH). This is a difficult reactions and requires harsh conditions.
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How is a primary alcohol oxidized to a carboxylic acid?
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Using Na2Cr2O7, K2Cr2O7 and CrO3 with H2O and H2SO4.
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How is an alkyl benzene to benzoic acid? What are the requirements?
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The C must have at least one H. It is done using KMnO4.
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Oxidative cleavake of an alkyne gives?
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Two carboxylic acids.
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Which is more reactive toward nucleophilic addition: an aldehyde or a ketone?
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Aldehyde. It has less steric hindrance and has less stability for the carbonyl carbon.
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Using NaBH4 or LAH, what is a ketone reduced to? What is an aldehyde reduced to?
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A ketone will yield a secondary alcohol, an aldehyde will yield a primary alcohol.
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What is the difference between NaBH4 and LAH, hindered LAH and DIBAL-H?
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NaBH4 selectively reduces the ALD or KET in the PRESENCE of other functional groups. LAH reduces ald and ket AND many other functional groups to a primary alcohol (or anime in the case of and amide and secondar in the case of a ketone). NaBH reduces aldehydes and ketones to primary/secondary alcohol. The hindered LAH will reduce a carboxylic acid derivative to an aldehyde and DIBAL will reduce an ester to an aldehyde.
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How are aldehydes oxidized to a carboxylic acid?
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Using any of the alcohol reducing agents or Tollens reagent.
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IR 3400
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OH or NH
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IR 3000-2850
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sp3 C-H
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IR 3100-3000
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C-H sp2
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IR 3300
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C-H sp
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IR 2100
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CtripleC or CtripleN
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IR 1700
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C=O
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IR 1600
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Aromatic C-C or C=C
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IR 1500
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C-C
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HNMR 1
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sp3 C
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HNMR 2
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C attached to pi system
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HNMR 3-4
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C attached to O
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HNMR 5-6
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sp2 C
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HNMR 7-8
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aromatic C
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HNMR 10
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Aldehyde C
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HNMR 11-12
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cooH (attached to O)
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What is Hoffman elimination?
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Bombarding NH2 with excess CHI (I-) to form a quartenary amine, which readily leaves in Ag2O forming an alkene.
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What is Hofmann Rearrangement?
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Adding Br2 and NaOH to an amide to form a primary amine.
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What is the order of shells filled according to the Aufbau principle (up to 6s)?
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1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s
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For the general rxn of MX(lower)n<------> M^n+ (aq) + nX-(aq) what would be the Ksp?
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Ksp=[M^n+][X-]^n or (in equation) Ksp=(s)(2s)^2. This comes from setting up the BCA table. Before, the [c] of both products is 0. The Change is +s and +2s and the After, at eq, is s and 2s. Sub that in to the original equation.
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When naming an ester, which part comes first, the cooh or the oh?
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You name the alcohol first, with the suffix yl and and the acid chain with the suffix oate to it (with a space).
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What is always the highest priority group in nomenclature?
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Cooh. It is ALWAYS number one.
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If two substituents are on the upper face of a cyclo hexane their relationship is....?
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Trans
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When can you use P, M or O designations for benzene? What do you use otherwise?
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Only when there are two substituents. If there are more you start the carbon that changes the name from benzene and give the other substituents the lowest possible numbers.
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Esters correspond to which biomolecules?
Amides? Acetals? |
Esters are lipids
Amides are peptide bonds Acetals are carbohydrates. |
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Do lone electron pairs count toward hybridization or no?
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Yes. This is most often seen in N and O.
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What is more important, getting all of the substituents with the lowest possible number or giving the highest priority group the lowest number?
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You need to get the priority group lowest first.
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What is it vinyl carbocation? What is it's stability?
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It is an ion RIGHT ON A 2X bond. It is very unstable.
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What causes a greater heat of combustion?
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Instability.
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Explain electron filling and ionization of the D set.
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It fills AR 4s2 3d1234 as if d were the higher energy orbital but it ionizes by removing the 4s electrons first because they are the furthest out. Doesn't make much sense, but that's how it is.
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Which atoms can have an expanded valence shell to accommodate more than 8 valence electrons?
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Atoms of the 2nd period CANNOT. Atoms of the 3rd period and beyond can. Sulfur for instance can be surrounded by 12 electrons or 8.
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What are the three exceptions to the octet rule?
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Some atoms don't have enough electrons to obey it, such as Be (BeH2 for instance). Some have odd numbers to they CAN'T obey it (most of these for free radicals like NO2). Those atoms in the 3rd period and below can use the d orbital to accommodate more than the classic 8 electrons.
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What are the metals on the periodic table?
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Anything on the left.
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What are the metalloids on the periodic table?
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They follow a semi-diagonal line down the periodic table starting with, B, going to Si, Ge, As, Sb, Te, Po, At.
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What are the non metals on the periodic table?
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Anything on the far right upper corner. To the right of B, Si, Ge, As, Sb, Te, Po, and At.
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What is the line notation for a galvanic cell? Which is written first, the anode or cathode? Which is written on the outside, the solids or the ions?
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The order goes anode cell first to show where the e- originate and the cathode last. The solids are written on the outside and the ions are written right before the sold bridge. The single lines represent phase changes (solid to aq) and the double lines represent a salt bridge.
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Which way do the negative ions in a salt bridge flow in a traditional galvanic cell?
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They flow toward the anode. In this cell, the solid is losing e- so positive ions are forming. The negative ions are needed to neutralize them. The opposite is true for the cathode. Cations move toward the cathode, anions move toward the anode.
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What is the equation for finding the standard cell potential from two reduction potentials?
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E cell= E cathode-E anode
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Which has a more negative standard reduction potential the anode or the cathode?
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The anode is more negative, meaning it has less of a tendency to be reduced or to gain electrons. A positive reduction potential means it's more like to be reduced, which occurs at the cathode.
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When balancing a redox equation, what happens to the standard reduction potentials if that half rxn is doubled?
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NOTHING. It stays the same!
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How does Eo cell relate to K?
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E cell=(0.0592v/n)log k
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When comparing the potential of an electrolytic cell with that of a galvanic cell, what happens? What is the main difference?
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The sign is changed, but the magnitude remains the same. The main difference is that the cell with the lower (nore negative) red. potential is actually reduced!!! This cell turns into the cathode! The cathode is still reduced and electrons flow to it, the opposite is still true for the anode.
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How do you find the density of a gas?
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The easy way to think of it is that d of a gas = g/L. At STP V=1L so n/V=P/RT. This will give us the number of moles per L. From this we can times the molar mass to it. If you times the molar mass to both sides at the beginning you get: d=(PM/RT).
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What is the equation for figuring out the possible number of stereo isomers of a compound?
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2^n where N represents to total number stereo centers.
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What is hypochlorite, chlorite, chlorate and perchlorate?
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Hypochlorite= ClO-
Chlorite= ClO2- Chlorate= ClO3- Perchlorate= ClO4- |
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What is Nitrate, azide or nitrite?
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Nitrate= NO3-
Nitrite= NO2- Azide=N3- |
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What is carbonate and bicarbonate (hydrogen carbonate)?
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Carbonate= CO3^2-
Bicarbonate= HCO3- |
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What is sulfate or sulfite?
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Sulfate=SO4^2-
Sulfite= SO3^2- |
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What is phosphate or phosphite?
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Phosphate=PO4^3-
Phosphite= PO3^3- |
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What is chromate?
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CrO4^2-
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What is permanganate?
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MnO4-
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In a first order reaction, what does the rate depend on?
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One of the reactants, raised to the first power (proportionate).
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What is a first order halflife dependent upon?
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NOTHING! No concentration effects it. It goes from 10-5 just as quickly as it goes from 100-50.
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What does a second order reaction depend on?
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The concentration of one reactant raised to the second power or the concentration of both reactants raised to the 1.
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How does concentration effect a second order half life?
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They are inversely proportional. The larger the concentration, the smaller the half-life.
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How does temperature effect reaction rates?
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It makes them occur more quickly. More collisions happen and they have more energy.
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What is another name for melting?
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Fusion.
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What is it called when molecules go directly from the solid phase to the gaseous phase? What is the opposite called?
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Sublimation is solid to gas, deposition is from gas to solid.
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What is a triple point?
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A point on the phase diagram where all three phases converge.
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When are Chromium reagents used and when is permanganate used?
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Chromium is used in an acidic environment, permangante in a basic envronment.
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What is the general result of adding KMNO4 or a Cr reagent to an alkenes, alkynes or alkylbenzenes?
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They give oxidative cleavage products. Benzene is cleaved at the benzyl carbon, as long as it has a benzylic hydrogen.
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What does Cr or KMNO4 do to primary alcohols? Secondary?
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1 to carboxylic acid 2 to ketones
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What does periodic (HIO4) acid do?
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cleavage of some carbon carbon double bonds (1,2 diols or alpha to carbonyl group).
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What does PCC do to primary alcohols? Secondary? Double bonds? When is it useful?
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1- Aldehydes 2- Ketones 3- NOTHING. This is useful when you have a double bond that you don't want to oxidize or when working with benzene substituents.
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What is the haloform reaction?
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Making COOH from C=OCh3. You add, I, Br or Cl to the methyl group and it leaves, the Oh adds and is neutralized.
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What does KMNO4 do to a double bond?
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Cleavage to form either COOH, decarboxylation and leave as CO2 (terminal double bond) or ketones (disubstituted).
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Ozone + alkene?
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Cleavage to form ketone or aldehyde.
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OsO4 to double bond?
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Cis diol.
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CrO3 to double bond?
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Like KMNO4, cleavage and dicarboxylic acid.
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COLD KMNO4 to double bond?
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cis diol.
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Na, NH3 to alkyne?
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Trans alkene
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NaBH4 reduces specifically....
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Aldehydes and ketones, not esters even.
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Pd and poison gives...
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A z alkene.
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H2/Pd to ketone?
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Reduces it to an alcohol (also effects alkenes).
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What are two ways to know that the rxn between iron (iii) oxide and magnesium chloride would yield FeCl3 and MgO?
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The first thing that tripped me up was not knowing what iron oxide is, which is unimportant. We know that O is 2- so it would have to be MgO and we know that Fe in this case is 3+ so 3Cls make sense. Also, just seeing the Os we can know that iron(iii) oxide is Fe2O3 because we know that O has a -2 charge so this is the only way to make it work!!!! Think! Don't get tripped up!
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What is an amide?
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NItrogen added to a COOH, taking the place of the OH.
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What is an amine?
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Nitrogen bound to 1, 2 or 3 carbons. No oxygen present.
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What is an imine?
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When an NH=C... Usually takes the place of an oxygen in a carbonyl.
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What is an azide?
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N3- or N3R
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What is a cyanate?
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N=C=O
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What is a nitrile?
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N=
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What does amphoteric mean?
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Amphoteric refers to a species that can act as both a bronsted acid or base.
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How do you OVER titrate something to a desired pH? How can you calculated how much you need to add?
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First, find out how much needs to be added to neutralize the solution. Then, find out how many (M) free hydrogen atoms you will need to have that desired pH. Let's say you want a pH of 4 and you added 30mL to 30mL to get a pH of 7 (neutral). For a pH of four you want 1*10^-4 or 0.0001 M of H+. We are at a total V of 60 ml. So to get 0.0001 M free H+ you must add about .006 ml of 1M HCl to get that pH for a total for 30.006 mL of 1M HCl.
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What is osmotic pressure? What is the eq to find it?
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The pressure required to stop osmosis. It is directly proportional to the concentration, in molarity, of the solute in solution. Pi is the symbol of O.P.. Pi=iMRT (R=.08206, i is van't Hoff factor, and T is temp K).
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What is the letter associated with the principle quantum number? What are its possible values?
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It is N. It corresponds to the size of the orbital or how far from the nucleus it is. It can be positive integers above zero ex 1, 2, 3, 4, etc.
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What is the letter associated with the angular momentum quantum number? What does it describe? What are its possible values? What do they correspond to?
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L. It describes the shapes of the orbitals. The possible values vary depending on the principle quantum number. They can be from 0 to n-1. So for N=1 there is only one L, 0. A value of 0 corresponds to an S orbital, 1=p, 2=d, 3=f.
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Orbitals with the same N are called? Same N and L?
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Shell and subshell.
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What is the magnetic quantum number? What are its values.
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It is m and refers to how many orbitals are in each subshell. It's possible values are from -L to +L. So for N=3 you have L = 0, 1, 2 or S, P, D. In the s subshell you have only one orbital (0). In the P subshell you have 3 orbitals (-1, 0, 1) in the D subshell you have 5 orbitals (-2, -1, 0, 1, 2).
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What is the Spin quantum number?
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It is the spin. An electron can have a - or + 1/2 spin.
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What is the Pauli Exclusion principle?
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No two electrons can have the same 4 Q#s.
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What is the aufbau principle?
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Building, adding electrons to the next orbital.
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What is Hund's rule?
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It states that the most stable conformation for electrons is one in which the same spin on electrons is maximized.
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What is the henderson hasselbach equation?
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pH=pKa+log (conj. base/weak acid)
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What is Lindlar's Catalyst? What does it do?
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It is a poisoned Pd metal. Since it is poisoned you can add it to an alkyne to form an alkene. H2 Pd/C would take it all the way to an alkane. It adds H2 to a triple bond in CIS fashion!!!!!
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How can you add H2 to an alkyne is trans fashion?
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You use Na in NH3.
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What is one Faraday? How many Faraday's are involved in the transfer of 5 moles of Nh4+ to Nh2-?
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The Faraday is the charge contained in one mole of electrons. One faraday is equal to 96,485 C or 96500 J/(V*mol e-). This would involve 10 fardays.
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If the second step is the slow step, how do you determine the rate law? If the first step is the slow step?
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If the second step is slow, it is K1*K2/K-1. If the first step is slow it would be just K1.
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If two compounds are catalytically hydrogenated to the same alkane, what does it mean if one has a higher heat of hydrogenation?
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A higher heat of hydrogenation means that it was less stable to start with. Maybe it was a cis double bond etc. it is higher in energy, therefor arriving to the same alkane releases more energy.
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If you are doing catalyzed hydrogenation and the double bond has one uncrowded side and one crowded side, which side are the H added to?
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They are added to the side complexed to the metallic surface and the less crowded side complexes to the surface. This results in a faster rxn.
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What does LAH to an alkyl halide produce? To an epoxide? What is the mechanism? Which side would it attack in a substituted epoxide?
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It is Sn2. An alkyl halide will make a plain alkane and an epoxide will open and form an alcohol. It will attack the least substituted side.
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What peroxyacid used for?
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For epoxidation of a double bond, an oxidation reaction. mCPBA is an example. Stereo chemistry is retained.
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Addition of KMnO4 or OsO4 results in...?
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Syn addition of H to a double bond.
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Oxidation of a terminal alkyne yields...?
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A carboxylic acid and CO2.
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What is the difference between PCC and other Cr reagents in oxidizing a primary alcohol?
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The PCC is milder and not in acid, so it takes it to an aldehyde. Other Cr reagents are in H+ so they make cooh.
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When is it useful to use NaBH4 over LAH?
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LAH will reduce a ketone, aldehyde and a carboxylic acid derivative like and ester. NaBH4 will only reduce a ketone or aldehyde. This allows for selective reduction.
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Does LAH or NaBH4 reduce alkenes?
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NO! They are nucleophilic reducing agents and pi bond are nucleophilic. It would try to deliver an H- to a pi bond which wouldn't work.
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When would you use DIBAL instead of LAH? When would you use LiAlH[OC(CH3)3]3 instead?
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LAH will reduce a substituted carbonyl to an alcohol or anime... DIBAL only takes them to a ketone. LiAlH[OC(CH3)3]3 will only reduce an acid chloride and it takes it to an aldehyde. You can take a COOH, turn it to an acid chloride (SOCL or PCL3) and then convert it to an aldehyde with LiAlH[OC(CH3)3]3.
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RMgX to:
Formaldehyde Other Aldehyde Ketone |
Form: 1o alcohol
Ald: 2o Alcohol Ket: 3o alcohol |
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RCuli to:
R'COCl To R'COOR" |
Cl: R'COR
RCOOR: NO RXN! Only reacts with acid chlorides. |
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RMgBr or Org. Li to Alpha-Beta unsaturated?
RCuLi to A,B unsautrated. |
1,2 addition. (Alcohol and R group on what was the carbonyl)
RCuLi is a slower reaction, so it adds R to the four (last carbon of double bond) and preserves the ketone in the net equation. |
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Ketone plus RNH2 and acid?
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Shiff base RN=C (need the hydrogens to do this rxn and transfer them to the oxygen. If not, the double bond remains between the two carbons a forming and enamine).
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Explain the difference between stereoselective and stereospecific.
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Selectivity is when a particular mechanism allows for formation of both products, like hydrogenation of an alkene using H2 and Pd/C, but one product is selectively produced over another. Specific is when the mechanism allows for formation of only one product. The other is impossible. Like an Sn2 rxn the stereochemistry of the starting material completely determines the product formed.
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What is the first law of thermodynamics? Work done by a system has a () sign. Work done on a system has a () sign.
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Energy cannot be created or destroyed, only transferred. (+) is done BY the system. Work done TO the system is (-).
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What is the second law of thermodynamics?
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A system moves to equilibrium and increases the entropy.
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Third law of thermodynamics.
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The entropy of a system at 0 K is 0.
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What does Isoelectric mean?
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Having the same number of electrons.
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What does K2Cr2O7 do to an aldehyde or alcohol?
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It takes them both to a carboxylic acid.
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What happens when Hg(OAc)2/H2O followed by NaBH4 add to a double bond?
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It undergoes markovnikov addition of an alcohol.
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