Getting Through College

Assign formal charges to atoms in organic structures and check their octets.

Identify polarized covalent bonds and label their partial charges.

Draw valid resonance contributors for a given organic species.

Rank resonance contributors by their relative importance.

Use pKa values to predict the favored side of a proton-transfer equilibrium.

Draw curved arrows for a proton-transfer reaction.

Assign hybridization and local geometry to atoms in an organic structure.

Distinguish sigma bonds from pi bonds in an organic structure.

Construct qualitative bonding and antibonding orbitals from interacting atomic orbitals.

Identify the HOMO and LUMO in a simple organic reactant pair.

Classify reactive sites as nucleophilic or electrophilic from charge, polarity, resonance, and orbital information.

Predict a bond-forming interaction from the symmetry and energy of the reacting frontier orbitals.

Draw staggered and eclipsed Newman projections for rotation about a carbon–carbon bond.

Rank conformations using torsional, steric, and gauche interactions.

Draw chair conformations of substituted cyclohexanes.

Rank substituted cyclohexane chairs using axial and equatorial interactions.

Assign R or S configuration to a stereogenic center using CIP priorities.

Classify a pair of structures as identical, constitutional isomers, enantiomers, or diastereomers.

Predict the stereochemical product of a reaction from a specified three-dimensional attack trajectory.

Interpret reactant, transition-state, intermediate, and product features on a reaction-coordinate diagram.

Use standard free-energy differences to compare product stability and equilibrium position.

Use activation free energies to compare reaction rates.

Distinguish kinetic control from thermodynamic control in a competing-reaction problem.

Apply the Hammond postulate to estimate transition-state structure.

Predict how temperature, concentration, solvent, and catalysts affect a reaction without changing its equilibrium incorrectly.

Recognize proton transfer, bond cleavage, bond formation, and rearrangement as elementary mechanistic steps.

Draw curved arrows that conserve atoms, charge, and electron pairs in an elementary step.

Infer missing intermediates or products from a sequence of curved arrows.

Propose a plausible multistep mechanism from given reactants and products.

Reject a proposed mechanism that violates electron bookkeeping, energetics, or stereochemical constraints.

Use a rate law, isotope effect, stereochemical result, or trapping result to compare competing mechanisms.

Draw the concerted orbital interaction and transition-state geometry of an SN2 reaction.

Predict SN2 rate trends from substrate structure, nucleophile strength, leaving-group ability, and solvent.

Predict inversion of configuration in an SN2 product.

Draw the stepwise ionization and capture mechanism of an SN1 reaction.

Predict SN1 rate trends and rearrangements from carbocation stability, leaving-group ability, and solvent.

Choose between SN1 and SN2 pathways for a specified set of reaction conditions.

Solve an exam-style substitution problem that requires product, mechanism, rate, and stereochemical predictions.

Identify beta hydrogens and draw the curved-arrow pattern for an E2 elimination.

Use anti-periplanar geometry to predict the stereochemical outcome of an E2 reaction.

Predict E2 regioselectivity from substrate structure and base sterics.

Draw the ionization and deprotonation steps of an E1 mechanism.

Predict rearrangement and alkene mixtures in an E1 reaction.

Choose among substitution and elimination pathways for a specified substrate and conditions.

Solve an exam-style competition problem involving SN1, SN2, E1, and E2 pathways.

Use frontier-orbital interactions to explain why an alkene reacts with an electrophile.

Draw the mechanism of electrophilic addition to an alkene.

Predict regioselectivity in an alkene addition from intermediate stability.

Predict syn or anti stereochemistry from a specified alkene-addition mechanism.

Explain how concerted and stepwise alkene additions produce different stereochemical outcomes.

Infer an alkene-addition mechanism from its regioselectivity, stereochemistry, and rearrangement behavior.

Solve an exam-style alkene reaction problem involving mechanism and product prediction.

Use resonance and frontier orbitals to explain the electrophilicity of a carbonyl carbon.

Draw a nucleophilic addition mechanism at an aldehyde or ketone.

Predict how substituents and protonation change carbonyl electrophilicity.

Draw a nucleophilic acyl-substitution mechanism through a tetrahedral intermediate.

Rank carboxylic acid derivatives by their susceptibility to nucleophilic acyl substitution.

Choose between carbonyl addition and acyl substitution from substrate structure and leaving-group ability.

Solve an exam-style carbonyl problem involving product prediction and mechanistic justification.

Work backward one step from a target molecule by identifying the bond formed in the final reaction.

Select reagents for a one-step transformation from a specified starting material to a target.

Design a two-step synthesis while preventing incompatible substitution, elimination, or addition pathways.

Track atoms and stereochemistry through a multistep reaction sequence.

Use kinetic, thermodynamic, orbital, and stereochemical evidence to defend a proposed synthesis.

Diagnose the conceptual cause of an error in a completed mechanism or synthesis.

Complete a timed cumulative problem set without notes and classify each error by topic.

Convert an error log into a targeted revision plan for the next CHEM 202Z assessment.