Organic Chemistry Practice Problems

Doing practice problems is the only way to master organic chemistry! At Chemistry Steps, you can find all the topics of Organic 1 and 2 and their associated practice problems. There are more than 2000 practice questions, and you can find them after each article listed below.

Here are some examples from the topics shown below. 

Note: These are sample practice problems for the new users. Please go to the topics, and you can practice problems after the articles, or in a separate post. 

Registered members can access all the quizzes and their solutions too.

 

Organic Chemistry 1 Practice Problems

Structure and Bonding Practice Problems

Convert the following condensed structures into Bond-line structures:

a) CH3CONHCH2OCH3

b) O(CH2)3CHCH3

c) CH3CHCHN(CH3)CH2CH3

d) (CH3)3CCH2CH2COOCH2CH3

e) CH3CH2CCCH2CO(CH2)2N(CH3)2

f) CH3CH2C(CH3)CHCH(CH2)4

g) (CH3)2CCHCH2OCH(CH3)CH2CN

h) CH3CH2CHClCHBrCH2CONHCH(CH3)2

i) (CH3)2CHCCCH2OCH(CH2Br)CH2CH3

j) CH3NHCHCCH3CHClCON(C2H5)2

Answers and Solutions

 

Molecular Representations

Practice Problems

Identify the delocalized lone pairs of electrons for each of the following compounds and draw at least one resonance structure using the delocalized lone pairs.

Answers and Solutions

 

Acids and Bases Practice Problems

Using the pKa table, determine a suitable reagent to deprotonate the following compounds. Each reagent can only be used once. Indicate the pKa values and write the second product as well.

Answers and Solutions

 

Alkanes and Cycloalkanes Practice Problems

Draw both chair conformation (ring-flip) and use the table to calculate the relative energy cost associated with each group in the axial position to determine the more stable chair conformation of each of the following compounds:

Answers and Solutions

 

Stereochemistry Practice Problems

Determine if each of the following alkenes has an E or Z configuration:

Answers and Solutions

Determine the relationship in each of the following pairs. Do the drawings represent constitutional isomers or stereoisomers, or are they just different ways of drawing the same compound? If they are stereoisomers, are they enantiomers or diastereomers?
Explain your answer by converting the drawings into the same representation, i.e., if you are comparing a Newman projection to a Fischer projection, you need to convert both into either a Newman or Fischer projection. Assign all the absolute configurations as R or S if you hesitate.

Answers and Solutions

 

Identify all the chiral centers in each molecule and determine the absolute configuration as R or S:

 

Answers and Solutions

 

Nucleophilic Substitution and Elimination Reactions

Practice Problems

Predict the mechanism as SN1, SN2, E1, or E2 and draw the major organic product formed in each reaction. Consider any regioselectivity and stereoselectivity where applicable:

Answers and Solutions

 

Reactions of Alkenes Practice Problems

Identify the reagents for each of the following addition reaction to an alkene:

Predict the product(s) that are formed after each step for reactions A-G. In each case, consider the formation of any chiral center(s) and draw all expected stereoisomers.

 

This is a comprehensive problem that covers the following topics and will serve as a review of all of them:

Substitution and elimination reactions. Particularly, substitution and elimination reactions of alcohols, the regio– and stereochemistry of E2 reactions and E2 reaction of cyclohexanes.

Mesylation and tosylation in Substitution and elimination reactions. 

Hydrohalogenation of alkenes according to the Markovnikov’s rule.

Radical hydrohalogenation of alkenes.

Hydroboration-Oxidation of Alkenes.

Halogenation of alkenes through halohydrin formation.

Syn and anti dihydroxilation of alkenes.

Elimination reactions: Zaitsev and Hoffman products.

Ozonolysis of Alkenes.

Attempt to solve the entire problem before accessing the answers!

The answers will give you the structure of the final product(s) only. Use this as a hint to determine the compounds formed after the first and second reactions.

Answers and Solutions

 

Reactions of Alkynes Practice Problems

Identify the reagents for each of the following reactions of internal and terminal alkynes:

 

On the following synthetic scheme, identify the reagents, in the correct order, that you would use to achieve the following synthetic transformations. Determine the structure of compounds A and B and the major organic products resulting from the alkyne.

 

 

Organic Chemistry 2 Practice Problems

NMR Spectroscopy Practice Problems

The 1H NMR spectrum of compound X (C4H8O2) is shown below. It also shows a strong IR absorption band near 1730 cm−1. Propose a structure for X.

Answers and Solutions

 

IR Spectroscopy

Label the functional groups and identify the correct compound based on the IR spectrum.

 

Radicals Practice Problems

Predict the products when each of the following compounds is treated with NBS under UV light:

Answers and Solutions

 

Alcohols Practice Problems

Predict the major organic product(s) for the following Grignard reactions of a ketone, aldehyde, ester, carbon dioxide and an epoxide:

Answers and Solutions

Predict the major organic product when the following alcohol is treated with each oxidizing agent:

Answers and Solutions

 

The Diels-Alder Reaction Practice Problems

For each Diels–Alder reaction, predict the major product(s) with correct stereochemistry when each cyclic diene is reacted with a dienophile:

Aromatic Substitution Practice Problems

Show how each compound can be synthesized from benzene and any other organic or inorganic reagents.

The order of reactions is very important! So, before every step, consider the ortho– , para– , or meta directing effect of the current group on the aromatic ring.

Devise a synthesis of each of the following compounds using an arene diazonium salt. They all require more than one step and you may select the desired regioisomer (for example the para product from an ortho, para mixture) when needed.

 

Answers and Solutions

 

Aldehydes and Ketones Practice Problems

Predict the major product(s) obtained when each of the following compounds undergoes hydrolysis in the presence of an acid:

Answers and Solutions

 

 Carboxylic Acids and Their Derivatives Practice Problems

Predict the major organic product(s) for each of the following reactions. They all involve carboxylic acid derivatives such as esters, acid chlorides, nitriles, anhydrides, and amides. You may also need to go over the reactions covered in earlier chapters, particularly, the Grignard and Gilman reagents, oxidizing and reducing agents and electrophilic aromatic substitutions.

A link to each topic encountered in a given problem will be provided in the answer tab.

 

Answers and Solutions

 

Alpha Carbon Chemistry – Enols and Enolates Practice Problems

This is a comprehensive practice problem on the alpha carbon chemistry. The topics covered range from the simple halogenation reactions of enols to multistep synthetic transformations.

To correctly answer these questions, you need to review the main principles of enolate chemistry – direct enolate alkylation, aldol condensation, crossed aldol condensation, alkylation using acetoacetic ester synthesis, malonic ester synthesis, the Stork enamine synthesis, Claisen condensation, Michael addition, and Robinson annulation.

Practice

Propose an efficient strategy to achieve each of the following synthetic transformations and show the structure of all the key intermediates.

 

Answers and Solutions

 

Check out our new synthesis puzzles!

 

CS Prime membership will also grant you access to multiple-choice quizzes!

 

Free

Nucleophilic Substitution and Elimination Practice Quiz

Free

Alkene Addition Reactions Practice Quiz

Free

Alkyne Naming and Reactions Practice Quiz

Free

Alcohols Quiz – Naming, Preparation, and Reactions

Free

Aldehydes and Ketones Reactions Practice Quiz

Free

Carboxylic Acids and Their Derivatives Quiz

Table of Contents

Structure and Bonding

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereochemistry

Energy Changes In Organic Chemistry

Nucleophilic Substitution Reactions

Alkenes: Structure, Stability, and Nomenclature

Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Nuclear Magnetic Resonance (NMR) Spectroscopy

Organic Structure Determination

Radical Reactions

Reactions of Alcohols

Ethers and Epoxides

Conjugated Systems

The Diels-Alder Reaction

Aromatic Compounds

Electrophilic Aromatic Substitution

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives-Nucleophilic Acyl Substitution

Alpha Carbon Chemistry: Enols and Enolates

Amines

Organic Synthesis Problems

Carbohydrates

All the practice problems are open to everyone for free! I have seen and prepared hundreds of exams for organic chemistry, and these practice problems are the types that you will find in your exams. Their difficulty varies from one-step to more advanced ones, including step organic synthesis problems.

After working on each question, you have the possibility to first check your answer and then refer to the step-by-step solution.

 

 

The practice problems are the only ones you get to do.

Multiple-choice quizzes might be the “easy” way of glancing through the key concepts and getting feedback on what you need to work on more.

These are also included in your Chemistry Steps membership.

 

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