Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
All Orgo Equations
| Question | Answer |
|---|---|
| HX (HCl, HBr, HI) | Hydrohalogenation. Markovnikov addition — H adds to less substituted carbon, X adds to more substituted carbon. Carbocation rearrangement possible. |
| HBr + ROOR (peroxide) | Radical addition. Anti-Markovnikov — H adds to more substituted carbon, Br adds to less substituted carbon. Only works with HBr. |
| H₂O + catalytic acid (H₂SO₄ or H₃O⁺) | Acid catalyzed hydration. Markovnikov addition of H and OH → alcohol. Carbocation rearrangement possible. No stereoselectivity. |
| ROH + catalytic acid * | Acid catalyzed addition of alcohol. Markovnikov addition of H and OR. Carbocation rearrangement possible. |
| 1) Hg(OAc)₂, H₂O, THF → 2) NaBH₄* | Oxymercuration-demercuration. Markovnikov addition of H and OH. No rearrangements. Stereorandom. |
| 1) BH₃, THF → 2) H₂O₂, NaOH* and syn or anti? | Hydroboration-oxidation. Anti-Markovnikov addition of H and OH. No rearrangements. Syn addition only. |
| Br₂ or Cl₂ in CCl₄* | Dihalogenation. Adds X and X → vicinal dihalide. Anti addition only. Halonium ion intermediate. |
| Br₂ or Cl₂ + H₂O and anti or syn? | Halohydrin formation. Adds X and OH. Anti addition. OH always goes to the more substituted carbon. |
| RCO₃H (e.g. mCPBA) | Epoxidation. Forms an epoxide. Both enantiomers produced if product is chiral. |
| 1) mCPBA → 2) H₃O⁺ or NaOH/H₂O * | Anti dihydroxylation. Adds two OH groups → vicinal diol. Anti addition. |
| Cold KMnO₄ / NaOH* | Syn dihydroxylation. Adds two OH groups → vicinal diol. Syn addition. |
| 1) OsO₄ → 2) H₂O₂ or NaHSO₃/H₂O * | Anti dihydroxylation. Adds two OH groups → vicinal diol. Anti addition. |
| 1) O₃ → 2) DMS or Zn/HOAc | Ozonolysis, reductive workup. Cleaves double bond. Carbon bonded to H → aldehyde. Carbon bonded to two carbons → ketone. |
| 1) O₃ → 2) H₂O₂ | Ozonolysis, oxidative workup. Cleaves double bond. Carbon bonded to H → carboxylic acid. Carbon bonded to two carbons → ketone. |
| Hot KMnO₄ | acidic workup. Oxidative cleavage. Same result as ozonolysis with oxidative workup — carboxylic acid or ketone depending on substitution. |
| H₂ + Pd, Pd/C, or Pt | Catalytic hydrogenation. Reduces alkene → alkane. Syn addition. Both enantiomers formed. |
| Terminal alkyne + HX (1 equiv.), no peroxide | Markovnikov vinyl halide (X on more substituted carbon) — alkene |
| Terminal alkyne + HX (2 equiv.), no peroxide | Geminal dihalide (both X on same carbon, more substituted) — alkane |
| Terminal alkyne + HBr / ROOR (1 equiv.) | Anti-Markovnikov vinyl halide (Br on terminal carbon) — alkene |
| Terminal alkyne + HBr / ROOR (2 equiv.) | Geminal dihalide (both Br on terminal carbon) — alkane |
| Unsymmetrical internal alkyne + HX (1 equiv.) | Mixture of two vinyl halide products — alkenes |
| Symmetrical internal alkyne + HX (1 equiv.) | One vinyl halide product only — alkene |
| Alkyne + excess Cl₂ or Br₂ (≥2 equiv.) | Tetrahaloalkane (four total halogens, two on each alkyne carbon) — alkane |
| Alkyne + H₂ / Pd, Pd/C, or Pt | Full reduction — alkane |
| Alkyne + H₂ / Lindlar's catalyst* | cis/Z — alkene |
| Alkyne + Li or Na / liquid NH₃* | trans/E — alkene |
| Terminal alkyne + HgSO₄ / H₂SO₄, H₂O | Enol → tautomerizes to ketone (Markovnikov) — ketone (carbonyl) |
| Terminal alkyne + R₂BH (Sia₂BH or 9-BBN) / THF, then H₂O₂ / NaOH* | Enol → tautomerizes to aldehyde (anti-Markovnikov) — aldehyde (carbonyl) |
| Terminal alkyne + 1) O₃ → 2) H₂O | Carboxylic acid + CO₂ — carboxylic acid |
| Unsymmetrical internal alkyne + 1) O₃ → 2) H₂O | Two different carboxylic acids — carboxylic acids |
| Symmetrical internal alkyne + 1) O₃ → 2) H₂O | Two equivalents of the same carboxylic acid — carboxylic acid |
| Terminal alkyne + NaNH₂ or NaH | Acetylide ion (deprotonated terminal carbon) — alkyne anion |
| Acetylide ion + methyl or primary alkyl halide | Elongated carbon chain via SN2 — alkyne |
| What is the product when a primary alcohol is treated with PCC, DMP/CH₂Cl₂, or Swern oxidation (DMSO/(COCl)₂, then NEt₃)? | An aldehyde |
| What is the product when a primary alcohol is treated with a strong oxidizing agent (KMnO₄, K₂Cr₂O₇, Na₂Cr₂O₇, H₂CrO₄, or CrO₃/H₂SO₄)? | A carboxylic acid |
| What is the product when a secondary alcohol is treated with any oxidizing agent? | A ketone |
| What happens when a tertiary alcohol is treated with an oxidizing agent? | No reaction — tertiary alcohols cannot be oxidized |
| What is the product when a ketone or aldehyde is treated with NaBH₄ or LiAlH₄, followed by H₃O⁺ workup? | Ketone → secondary alcohol; Aldehyde → primary alcohol |
| What is the product when an ester or carboxylic acid is treated with LiAlH₄, then H₃O⁺? | A primary alcohol |
| What is the product when an ester or carboxylic acid is treated with NaBH₄, then H₃O⁺? | No reaction — NaBH₄ is too weak to reduce esters or carboxylic acids |
| What are the reagents and product of a Clemmensen reduction? Reagents: Zn(Hg) and HCl. | The carbonyl group (ketone or aldehyde) is reduced to an alkane |
| What are the reagents and product of a Wolff-Kishner reduction? Reagents: H₂NNH₂ (hydrazine) and KOH/heat. | Product: The carbonyl group (ketone or aldehyde) is reduced to an alkane |
| What is the product when an aldehyde or ketone is reacted with an alcohol under basic conditions? | A hemi-acetal (from aldehyde) or hemi-ketal (from ketone) |
| What is the product when an aldehyde or ketone is reacted with an alcohol under acidic conditions (cat. H⁺)? | An acetal (from aldehyde) or ketal (from ketone) — the carbonyl oxygen is replaced by two alkoxy groups |
| What is the product when an acetal or ketal is treated with H₃O⁺ (aqueous acid)? | The original aldehyde or ketone is regenerated (hydrolysis) |
| What is the product when a ketone or aldehyde reacts with a diol under acidic conditions (e.g., H₂SO₄)? | A cyclic acetal or cyclic ketal (used as a protecting group) |
| What is the product when an aldehyde or ketone is reacted with a primary amine (1° amine) with catalytic acid? | An imine (contains a C=N double bond) |
| What is the product when an aldehyde or ketone is reacted with a secondary amine (2° amine) with catalytic acid? | An enamine (contains a C=C double bond with nitrogen single-bonded to one alkene carbon) |
| What is the product when an imine or enamine is treated with H₂O and catalytic acid? * | The original ketone (hydrolysis) |
| How is a Grignard reagent formed, and what are the conditions? | An alkyl halide is reacted with elemental magnesium (Mg) in an aprotic solvent (THF or Et₂O), producing R-MgBr |
| What is the product when a Grignard reagent attacks an aldehyde, ketone, or ester followed by H₃O⁺ workup? | Secondary alcohol for the aldehyde, tertiary for the ketone |
| What happens when a Grignard reagent is exposed to water or other acidic protons? | The Grignard is destroyed — it abstracts a proton from water and produces an alkane, ruining the reagent |
| What is the product of the Wittig reaction between a Wittig reagent (ylide) and an aldehyde or ketone? | There's a double bond where the O was and the section originally attached to the PPh₃, P=O is released as a byproduct |
| What is a hemi-acetal? | An aldehyde that reacted with one alcohol. Has both -OH and -OR on the same carbon. |
| What is an acetal? | An aldehyde that reacted with two alcohols. Has two -OR groups on the same carbon, no -OH. |
| What is a hemi-ketal? | A ketone that reacted with one alcohol. Has both -OH and -OR on the same carbon. |
| What is a ketal? | A ketone that reacted with two alcohols. Has two -OR groups on the same carbon, no -OH. |
| KMnO₄, H₂CrO₄, or CrO₃/H₂SO₄ (Jones reagent) acting on a primary alcohol | Carboxylic acid |
| 1) Mg, 2) CO₂, 3) H₃O⁺ acting on an alkyl halide | Carboxylic acid (via Grignard reagent) |
| SOCl₂ or PCl₃ acting on a carboxylic acid | Acid chloride |
| H₃O⁺ (or 1) NaOH, 2) H₃O⁺) acting on an acid chloride or acid anhydride | Carboxylic acid |
| ROH with [H⁺], or 1) NaOR, 2) H₃O⁺ acting on an acid chloride or acid anhydride* | Ester |
| R₂NH acting on an acid chloride or acid anhydride | Amide |
| 1) excess LiAlH₄, 2) H₃O⁺ acting on an acid chloride or acid anhydride | Primary alcohol |
| 1) excess RMgX, 2) H₃O⁺ acting on an acid chloride or acid anhydride* | Tertiary alcohol |
| R₂CuLi acting on an acid chloride or acid anhydride* | Ketone |
| ROH with [H⁺] acting on a carboxylic acid* | Ester + H₂O (Fischer esterification) |
| 1) NaOH, 2) H₃O⁺ acting on an ester | Carboxylic acid (saponification) |
| Acid or base with alcohol acting on an ester * | New ester with replaced alkoxy group (transesterification) |
| 1) 2 eq. Grignard (RMgX), 2) H₃O⁺ acting on an acid chloride, acid anhydride, or ester* | Tertiary alcohol (goes through ketone intermediate) |
| 1) LiAlH₄, 2) H₃O⁺ acting on an ester | Primary alcohol |
| 1) LiAlH₄, 2) H₃O⁺ acting on an acid chloride | Primary alcohol |
| 1) LiAlH₄, 2) H₂O acting on an amide | Amine |
| 1) DIBAL-H at −70°C, 2) H₂O acting on an ester | Aldehyde |
| 1) LTBA, 2) H₂O acting on an acid chloride | Aldehyde |
| Br₂ / NaOH acting on a primary amide | (Hofmann rearrangement) Primary amine (one carbon shorter; carbonyl carbon is lost) |
| Cyanide ion (NaCN) acting on an alkyl halide | Nitrile |
| 1) LiAlH₄, 2) H₂O acting on a nitrile | Primary amine |
| H₃O⁺ with heat acting on a nitrile | Carboxylic acid (nitrile hydrolysis) |
| HCN acting on an aldehyde or ketone | Cyanohydrin (−OH and −CN on the same carbon) |
| 1) Grignard reagent (RMgX), 2) H₃O⁺ acting on a nitrile* | Ketone (via imine intermediate) |
| H₂O / acidic aqueous conditions with heat acting on an amide * | Carboxylic acid (amide hydrolysis) |
| HI / HBr / HCl + alcohol | Converts alcohol to alkyl halide. Tertiary/secondary → SN1; primary → SN2. Requires protonation of OH first. |
| PBr3 + primary or secondary alcohol | Converts to alkyl bromide with inversion of stereochemistry (SN2). |
| SOCl2 + primary or secondary alcohol | Converts to alkyl chloride with inversion of stereochemistry (SN2). |
| TsCl (tosyl chloride) + alcohol | Converts OH to tosylate (good leaving group) with retention of stereochemistry. |
| MsCl (mesyl chloride) + alcohol | Converts OH to mesylate (good leaving group) with retention of stereochemistry. |
| NaH + alcohol, then alkyl halide | Deprotonates alcohol to form alkoxide, which attacks alkyl halide via SN2 to form an ether. (Williamson Ether Synthesis) The ether section from the halide adds to the alcohol |
| Strong acid (H⁺) + primary alcohol | Protonates OH; second alcohol molecule attacks via SN2, water leaves — forms a symmetrical ether. |
| HBr or HI (excess) + ether | Cleaves ether into two alkyl halides. HCl and HF cannot do this. |
| HBr or HI + aryl/vinyl ether | Cleaves to give one alkyl halide + one alcohol (aryl/vinyl carbon cannot undergo nucleophilic attack). |
| mCPBA + alkene | Epoxidizes the double bond, forming an epoxide. |
| Nucleophile + epoxide in basic conditions | SN2 attack at the less substituted carbon; followed by acidic workup to protonate the alkoxide. |
| Grignard reagent (RMgBr) + epoxide | Basic conditions; attacks less substituted carbon SN2 style, then H₃O⁺ workup gives alcohol. (Grignard cannot exist in acidic conditions.) |
| Organolithium (RLi) or LiAlH₄ + epoxide | Same as Grignard — basic conditions, attacks less substituted carbon, acidic workup. |
| Nucleophile + epoxide in acidic conditions (e.g., HCl, H₂O/H⁺, ROH/H⁺) | Epoxide oxygen is protonated first, weakening the bond to the more substituted carbon; nucleophile attacks the more substituted carbon via SN2. |
| NaOCH₃ (or NaOR) + epoxide | Basic conditions; methoxide attacks less substituted carbon, acidic workup gives a β-methoxy alcohol. |
| CH₃OH + H⁺ + epoxide | Acidic conditions; methanol attacks more substituted carbon, giving a β-methoxy alcohol (regiochemistry opposite to basic conditions). |
| NaOH or NaNH₂ added to a carbonyl compound | Removes an alpha hydrogen to form a resonance-stabilized enolate ion |
| LDA added to a carbonyl compound | Strong, bulky base that deprotonates the less sterically hindered alpha carbon to form an enolate |
| What is an enolate ion? | The resonance-stabilized conjugate base formed when a strong base removes a hydrogen from the alpha carbon (the carbon adjacent to a carbonyl group) of an aldehyde, ketone, or ester. |
| NaOH + two identical aldehydes/ketones | Aldol addition → forms a β-hydroxy aldehyde or β-hydroxy ketone (aldol/ketol) |
| NaOH + heat applied to a β-hydroxy carbonyl compound | Aldol condensation → dehydration occurs, forming an α,β-unsaturated carbonyl compound |
| NaOH + two different aldehydes or ketones | Crossed aldol condensation → α,β-unsaturated carbonyl compound (with double bond) |
| NaOH + heat applied to a β-hydroxy carbonyl compound | Aldol condensation → dehydration occurs, forming an α,β-unsaturated carbonyl compound |
| NaOH + two different aldehydes or ketones | Crossed aldol condensation → α,β-unsaturated carbonyl compound, only if you add heat, there is a double bond |
| Alkoxide base (matching the ester's alkoxy group) + two esters | Claisen condensation → forms a β-keto ester; the alkoxide kicks off as a leaving group, one ester at an end and two ketones, no double bonds |
| Alkoxide base + diester (two ester groups on the same molecule), then H₃O⁺ * | Dieckmann condensation (intramolecular Claisen) → forms a cyclic β-keto ester |
| Malonic ester (EtO O on both sides originally) + NaOR → R₁X → (optional: NaOR → R₂X) → H₃O⁺ + heat* | Malonic ester synthesis → produces a substituted carboxylic acid; heat causes decarboxylation of the beta carboxyl group |
| Acetoacetic ester + NaOR → R₁X → (optional: NaOR → R₂X) → H₃O⁺ + heat | Acetoacetic ester synthesis → produces a substituted methyl ketone; heat causes decarboxylation, ester on one end and ketone at the other, nucleophile substitution would be in the middle |
| Stabilized nucleophile (Michael donor) + α,β-unsaturated carbonyl compound (Michael acceptor) | Michael addition (1,4-addition) → nucleophile adds to the β carbon; oxyanion is protonated to an enol, then tautomerizes to a ketone |
| 2 equivalents of organolithium + CuBr → product reacted with α,β-unsaturated carbonyl, then H₃O⁺ * | Gilman reagent (organocuprate, R₂CuLi) acts as Michael donor → alkyl group adds to the β carbon; tautomerization reforms the carbonyl - gets rid of the double bond and just attaches the part next to the Li |
| X₂ (Cl₂, Br₂, or I₂) + H₃O⁺ added to a ketone * | Acidic alpha halogenation → only one halogen replaces one alpha hydrogen |
| X₂ (Cl₂, Br₂, or I₂) + NaOH added to a ketone | Basic alpha halogenation → all alpha hydrogens are replaced with halogen atoms |
| Methyl ketone + excess X₂ (Cl₂, Br₂, or I₂) + NaOH, then H₃O⁺ | Haloform reaction → produces a carboxylic acid + haloform (CHX₃); works best when the other alkyl group has no alpha hydrogens (e.g., tert-butyl or phenyl) |
| Ketone + D₂O + acid or base | Alpha deuteration → all alpha hydrogens are replaced with deuterium atoms (occurs under both acidic and basic conditions) |
| Stabilized nucleophile (Michael donor) + α,β-unsaturated carbonyl compound (Michael acceptor) | Michael addition (1,4-addition) → nucleophile adds to the β carbon; oxyanion is protonated to an enol, then tautomerizes to a ketone |
| Common Michael Donors* | β-diketone enolates, enamines, α-cyano enolates, malonate enolates, Gilman reagents (R₂CuLi) |
| Common Michael Acceptors | α,β-unsaturated ketones, α,β-unsaturated aldehydes, α,β-unsaturated esters, α,β-unsaturated nitriles, α,β-unsaturated nitro compounds |
| Na, NH₃, EtOH* | reduces aromatic ring to non-aromatic ring with 2 pi bonds on opposite sides. When an EDG is present on the ring, the carbon it is attached to is not reduced. When an EWG is present on the ring, the carbon it is attached to is reduced. |
| Br₂ + FeBr₃ or AlBr₃ | bromobenzene |
| Cl₂ + FeCl₃ or AlCl₃ | chlorobenzene |
| alkyl halide + AlCl₃ | alkylbenzene (watch for carbocation rearrangement), so it will usually make the branched thing instead of a chain. |
| RCOCl + AlCl₃ | acylbenzene/ketone (no rearrangement) |
| Zn(Hg), HCl, heat (in FC) | can be used to turn the Alkyl ketone product into a straight chain propyl group, essentially carbonyl to alkane |
| H₂NNH₂, KOH, heat (in FC) | can be used to turn the Alkyl ketone product into a straight chain propyl group, essentially carbonyl to alkane |
| HNO₃ + H₂SO₄ | adds NO₂ to ring |
| SO₃ + H₂SO₄ | adds SO₃H to ring |
| CO + HCl + AlCl₃ * | adds CHO to ring |
| KMnO₄ + NaOH + heat then H₃O⁺, or Na₂Cr₂O₇ + H₂SO₄ | benzylic carbon → COOH (rest of chain cleaved; no reaction if benzylic carbon has no H) |
| ArNH₂ + NaNO₂ + HCl → | Ar–N₂⁺ (Diazonium Formation) |
| Diazonium + HBF₄ | ArF |
| Diazonium + KI | ArI |
| Diazonium + CuBr | ArBr |
| Diazonium + CuCl | ArCl |
| Diazonium + CuCN | ArCN |
| Diazonium + H₃O⁺ + heat | ArOH |
| Diazonium + H₃PO₂ | ArH |
| What functional groups can ONLY be introduced via diazonium salts? * | Iodo (–I), fluoro (–F), phenol (–OH), and nitrile (–CN) substituents on benzene |
| What are the 3 rules for aromaticity? | 1) Cyclic 2) Fully conjugated and planar (no sp3 atoms in ring) 3) Hückel's rule: # of pi electrons = 4n+2. Remember that + is an empty orbital, - is two extra electrons |
| What makes a compound anti-aromatic? | Satisfies rules 1 & 2 but fails Hückel's rule (pi electrons = 4n) |
| What makes a compound non-aromatic? | Fails rule 1 or 2 (not cyclic, not fully conjugated/planar) |
| Why is cyclooctatetraene non-aromatic rather than anti-aromatic? | It adopts a tub conformation — it is not planar, so it fails rule 2 before Hückel's rule even applies. |
| When is a compound considered aromatic-stabilized acid? | When deprotonation produces an aromatic conjugate base (more stable → more acidic) |
| Is a compound acidic if deprotonation makes it anti-aromatic? | No — anti-aromatic conjugate base is unstable, so the compound is not considered acidic |
| When is a compound likely to undergo SN1? | When loss of the leaving group produces an aromatic carbocation intermediate |
| Will a compound undergo SN1 if the carbocation intermediate would be anti-aromatic? | No — the instability of the anti-aromatic intermediate prevents the reaction |
| What are the two steps of every EAS reaction? | 1) Nucleophilic attack on electrophile → sigma complex (arenium ion) — rate-limiting step 2) Base deprotonates sigma complex → aromaticity restored |
| What prevents FC alkylation/acylation from occurring? | Strong EWGs (e.g., NO₂) — they deactivate the ring too much |
| Why do NH₂, NHR, or NR₂ groups also block FC reactions? | Their lone pairs react with AlCl₃ instead of the alkyl/acyl halide, tying up the catalyst |
| What types of groups are ortho/para directors vs meta directors? | Electron donating groups (EDGs) = ortho/para directors; Electron withdrawing groups (EWGs) = meta directors |
| Are halogens activating or deactivating? Ortho/para or meta? | Mildly deactivating, but ortho/para directors (exception to the EWG = meta rule) |
| Alkyl groups vs acyl groups — which position do they direct? | Alkyl groups = ortho/para directors; acyl groups = meta directors. The only things with O that are still ortho/para are OR, OH, amides |
| How do you get ortho/para substitution starting from a carbonyl-substituted ring? | Reduce the carbonyl first (Clemmensen or Wolff-Kishner), then perform EAS |
| When does the + sign actually count as extra electrons? | When there's the possibility of delocalization; the O in the ring must have space to move |
| When there's multiple substituents, which one does the directing? | The one that's more activating |
| Br₂ / hν | Free radical bromination; adds Br to the most substituted carbon; produces racemic mixture if chiral center is created |
| Cl₂ / hν | Free radical chlorination; adds Cl to carbon but lacks regioselectivity; produces a mixture of products at various positions - usually two on the compound itself |
| NBS / hν | Allylic or benzylic bromination; keeps Br₂ concentration low to prevent alkene addition; allylic gives mixture of products due to resonance, benzylic gives single product at benzylic carbon only; fails if no benzylic/allylic hydrogen present |
| Conjugated diene (s-cis) + alkene or alkyne dienophile | Forms a six-membered ring; exothermic; stereochemistry of dienophile is retained in product; cyclic diene gives bicyclic endo-favored product |
| HBr (cold) | 1,2-addition via allylic carbocation intermediate; kinetic product; monosubstituted alkene formed |
| HBr (hot) | 1,4-addition via allylic carbocation intermediate; thermodynamic product; more stable disubstituted alkene formed |
| Rank carbon radical stability from least to most stable. | Vinylic < methyl < primary < secondary < tertiary < allylic < benzylic |
| What are the three steps of a free radical reaction? | 1) Initiation – homolytic cleavage forms two radicals (endothermic, rate-limiting). 2) Propagation – a radical reacts with a stable molecule to generate a new radical. 3) Termination – two radicals combine to form a stable molecule. |
| What conformation must the diene be in for a Diels-Alder reaction, and why? | s-cis conformation — both double bonds must be on the same side of the central sigma bond so the ends of the diene can reach the dienophile. s-trans dienes cannot react. |
| What happens to the bonds in a Diels-Alder reaction energetically? | Three pi bonds become one pi bond and two sigma bonds. Since sigma bonds are more stable than pi bonds, the reaction is exothermic. |
| What is the endo rule in Diels-Alder reactions with cyclic dienes? | When a cyclic diene reacts, cis substituents on the dienophile end up in the endo position (underside of the new six-membered ring) in the major product. Endo is highly favored over exo. |
| Why is 1,2-addition the kinetic product? | It forms faster and has a lower activation energy, so it is favored under cold/low-energy conditions. |
| Why is 1,4-addition the thermodynamic product? | It produces a more substituted (disubstituted) alkene, which has lower Gibbs free energy and is more stable than the monosubstituted 1,2-addition product. |
| What is kinetic control vs. thermodynamic control? | Kinetic control = product determined by rate of formation (faster reaction wins). Thermodynamic control = product determined by relative stability (more stable product wins). |
| What does IR spectroscopy identify? | The functional groups present in a molecule. |
| What requirement must a bond meet to show up on an IR spectrum? | It must have a net dipole moment. Symmetrical bonds (O₂, N₂, C₂H₂, C₂H₄) do not appear. |
| IR absorption frequencies and appearances — Alcohol (-OH)? | 3200–3500 cm⁻¹, large broad peak. |
| IR absorption — Amine (N-H)? | 3200–3500 cm⁻¹, sharp peak. Primary amine: 2 peaks. Secondary amine: 1 peak. |
| IR absorption — Carboxylic Acid (-COOH)? | 2500–3500 cm⁻¹, broad jagged peak. |
| IR absorption — Nitrile (C≡N)? | 2200–2250 cm⁻¹, medium peak. |
| IR absorption — Carbonyl (C=O)? | 1700–1750 cm⁻¹, large sharp peak. |
| IR absorption — Aromatic (C=C)? | 1450–1600 cm⁻¹, medium peak. |
| What is the fingerprint region in IR spectroscopy? | 400–1500 cm⁻¹, produces a complicated pattern of peaks unique to each molecule. |
| What is chemical shift in NMR and what affects it? | The position of a signal on the spectrum (in ppm). Protons near electronegative atoms are deshielded → appear downfield (left). Protons with more electron density are shielded → appear upfield (right). |
| ¹H NMR chemical shift — Carboxylic acids (RCO₂H)? | ~12 ppm (far downfield) |
| ¹H NMR chemical shift — Aldehydes (RCHO)? | ~9–10 ppm |
| ¹H NMR chemical shift — Aromatic protons (ArH)? | ~6–8 ppm |
| ¹H NMR chemical shift — sp² C–H (alkene protons)? | ~5–6 ppm |
| ¹H NMR chemical shift — sp³ C–H (alkyl protons)? | ~1–3 ppm |
| What is TMS and what is its chemical shift? | Tetramethylsilane, the reference standard. Chemical shift = 0 ppm. |
| ¹³C NMR chemical shift — Ketone/Aldehyde carbonyl carbon? | ~200–220 ppm (far downfield) |
| ¹³C NMR chemical shift — Ester, amide, acid chloride, carboxylic acid carbonyl carbon? | ~160–180 ppm |
| ¹³C NMR chemical shift — Aromatic carbons? | ~120–160 ppm |
| ¹³C NMR chemical shift — sp² C (alkene carbons)? | ~100–150 ppm |
| ¹³C NMR chemical shift — sp³ C (alkyl carbons)? | ~0–80 ppm |
| Degrees of unsaturation formula? | (2C + 2 + N − X − H) / 2. Each degree = one pi bond or one ring. |
| What does mass spectrometry measure and how does it work? | Measures the mass of a compound. Sample is vaporized, ionized, fragmented, then fragments are separated by their mass-to-charge ratio (m/z) using a magnetic field. |
| What is the molecular ion peak in mass spectrometry? | The tallest peak in the rightmost section of the spectrum. Represents the intact ionized molecule — gives the compound's molecular mass. |
| What is the base peak in mass spectrometry? | The tallest peak in the entire spectrum (100% intensity). Corresponds to the most stable fragment. Not necessarily the molecular ion peak. |
| What does UV-Vis spectroscopy measure? | The wavelengths of UV and visible light absorbed by molecules with conjugated pi bonds. |
| What does a higher λmax indicate in UV-Vis? | More conjugated pi bonds. Greater conjugation = lower energy = longer wavelength absorbed. |
| What is liquid-liquid extraction and what apparatus is used? | A separation technique using two immiscible solvents (one aqueous, one organic) in a separatory funnel. Compounds partition based on polarity — hydrophobic → organic layer, hydrophilic/ionic → aqueous layer. |
| How can extraction separate compounds based on acidity? | Adding a base (e.g., NaOH) deprotonates acidic compounds (e.g., carboxylic acids) → charged → migrate to aqueous layer. Neutral compounds stay in organic layer. |
| How can extraction separate compounds based on basicity? | Adding an acid (e.g., HCl) protonates basic compounds (e.g., amines) → charged → migrate to aqueous layer. Neutral compounds stay in organic layer. |
| How does TLC work and what is its purpose? | Used to monitor reactions. Polar silica stationary phase, solvent mobile phase. Nonpolar compounds travel faster (higher Rf). Polar compounds interact more with silica → travel slower (lower Rf). |
| How does column chromatography differ from TLC? | Same principles, but used to actually separate large amounts. Less polar compounds elute first; more polar compounds elute last. |
| How does gas-liquid chromatography work? | Stationary phase = high boiling point liquid; mobile phase = gas. Used to determine relative abundance of compounds. Higher boiling point → slower travel → longer retention time. |
| When is simple vs. fractional distillation used? | Simple distillation: boiling points differ by ≥50°C. Fractional distillation: boiling points differ by ≤25°C (closer together). The lower boiling point liquid is collected first in the receiving flask. |
| What is recrystallization and when is it used? | Purifies solids. Solid is dissolved in hot solvent, then cooled → pure crystals form. Impurities remain in solution. Pure crystals are collected by vacuum filtration. |
| Bromine Test — purpose and result? | Detects alkenes/alkynes. Treat with Br₂ in CCl₄. Positive: brown color disappears. Negative (alkane): color remains. |
| Baeyer Test — purpose and result? | Detects alkenes/alkynes. Treat with dilute KMnO₄. Positive: purple turns brown (MnO₂ precipitate). Negative: remains purple. |
| Silver Nitrate in Alcohol Test — purpose and result? | Detects alkyl halides. Treat with AgNO₃ in alcohol. Positive: silver halide precipitate forms. |
| Iodoform Test — purpose and result? | Detects methyl ketones and acetaldehyde. Treat with I₂ + NaOH. Positive: yellow CHI₃ precipitate forms. |
| Tollens' Test — purpose and result? | Detects aldehydes. Treat with Tollens' reagent (Ag₂O in NH₃). Positive: silver mirror forms. |
| Lucas Test — purpose and result? | Distinguishes secondary/tertiary/benzylic alcohols from primary. Treat with ZnCl₂ + HCl. Positive: cloudiness (2° or 3° alcohol). Negative: clear (primary alcohol). |
| Jones Test — purpose and result? | Identifies primary and secondary alcohols. Treat with CrO₃ in H₂SO₄. Positive: orange → blue-green color change. Negative: no color change. |
| Methyl m/z = | 15 |
| Propyl group and methyl ketones m/z = | 43 |
| Isopropyl group m/z = | 43 |
| Butyl group m/z = | 57 |
| Bromine m/z ratio | 1:1 |
| Chlorine m/z ratio | 3:1 |
| Sulfur m/z ratio | 22 : 1 |
Created by:
smurtab