Chemistry Steps Study Hall
Have a question, need clarification, or want a quick walkthrough?
Just drop it below – upload a file, paste a problem, or draw a structure.


❗️ ❗️ ❗️ CS members, get exclusive access to an interactive chemistry board where you can get help in real time by drawing structures, uploading files, communicating via chat, and even hop on a video call to walk through mechanisms, problem sets, or exam questions. Whether you’re stuck on a synthesis, confused about stereochemistry, or just want quick clarification, the board gives you a direct, hands-on way to get help exactly when you need it.
Whenever online, you can also join a video call with me right in the board for a mini tutoring session. 📕💻
This content is for registered users only.
By joining Chemistry Steps, you will gain instant access to the answers and solutions for all the Practice Problems, including over 40 hours of problem-solving videos, Multiple-Choice Quizzes, Puzzles, Reaction Maps, and the powerful set of Organic Chemistry 1 and 2 Summary Study Guides.
Stuck? Drop your question here or on the board – get a quick fix in minutes.
Structure and Bonding
- Lewis Structures in Organic Chemistry
- Valency and Formal Charges in Organic Chemistry
- How to Determine the Number of Lone Pairs
- Bonding Patterns in Organic Chemistry
- sp3, sp2, and sp Hybridization in Organic Chemistry with Practice Problems
- How to Quickly Determine The sp3, sp2, and sp Hybridization
- Bond Lengths and Bond Strengths
- VSEPR Theory – Molecular and Electron Geometry of Organic Molecules
- Dipole-dipole, London Dispersion and Hydrogen Bonding Interactions
- Dipole Moment and Molecular Polarity
- Boiling Point and Melting Point in Organic Chemistry
- Boiling Point and Melting Point Practice Problems
- Solubility of Organic Compounds
- General Chemistry Overview Quiz
Molecular Representations
- Bond-Line or Skeletal Structures
- Functional Groups in Organic Chemistry with Practice Problems
- Bond-line, Lewis, and Condensed Structures with Practice Problems
- Curved Arrows with Practice Problems
- Resonance Structures in Organic Chemistry with Practice Problems
- Rules for Drawing Resonance Structures
- Major and Minor Resonance Contributor
- How to Choose the More Stable Resonance Structure
- Drawing Complex Patterns in Resonance Structures
- Localized and Delocalized Lone Pairs with Practice Problems
- Molecular Representations Quiz
Acids and Bases
- Acids and Bases – General Chemistry
- Organic Acids and Bases
- Organic Acid-Base Mechanisms
- Acid Strength and pKa
- How to Determine the Position of Equilibrium for an Acid-Base Reaction
- Inductive and Resonance (Mesomeric) Effects
- Factors That Determine the pKa and Acid Strength
- How to Choose an Acid or a Base to Protonate or Deprotonate a Given Compound
- Lewis Acids and Bases
- Basicity of Amines
- Organic Acids and Bases Practice Problems
- Organic Acids and Bases Quiz
Alkanes and Cycloalkanes
- Naming Alkanes by IUPAC Nomenclature Rules Practice Problems
- Naming Bicyclic Compounds
- Naming Bicyclic Compounds-Practice Problems
- How to Name a Compound with Multiple Functional Groups
- Primary, Secondary, and Tertiary Carbon Atoms in Organic Chemistry
- Constitutional or Structural Isomers with Practice Problems
- Degrees of Unsaturation or Index of Hydrogen Deficiency
- The Wedge and Dash Representation
- Sawhorse Projections
- Newman Projections with Practice Problems
- Staggered and Eclipsed Conformations
- Conformational Isomers of Propane
- Newman Projection and Conformational Analysis of Butane
- Newman Projection of Chair Conformation
- Gauche Conformation
- Gauche Conformation, Steric, Torsional Strain Energy Practice Problems
- Ring Strain
- Steric vs Torsional Strain
- Conformational Analysis
- Drawing the Chair Conformation of Cyclohexane
- Ring Flip: Drawing Both Chair Conformations with Practice Problems
- 1,3-Diaxial Interactions and A value for Cyclohexanes
- Ring-Flip: Comparing the Stability of Chair Conformations with Practice Problems
- Cis and Trans Decalin
- IUPAC Nomenclature Practice Problems
- IUPAC Nomenclature Summary Quiz
- Alkanes and Cycloalkanes Practice Quiz
Stereochemistry
- How to Determine the R and S Configuration
- The R and S Configuration Practice Problems
- What is Nonsuperimposable in Organic Chemistry
- Chirality and Enantiomers
- Diastereomers-Introduction and Practice Problems
- Enantiomers vs Diastereomers
- Cis and Trans Isomers
- E and Z Alkene Configuration with Practice Problems
- Enantiomers, Diastereomers, the Same or Constitutional Isomers with Practice Problems
- Configurational Isomers
- Optical Activity
- Specific Rotation
- Racemic Mixtures
- Enantiomeric Excess (ee): Percentage of Enantiomers from Specific Rotation with Practice Problems
- Symmetry and Chirality. Meso Compounds
- Fischer Projections with Practice Problems
- R and S Configuration in the Fischer Projection
- R and S configuration on Newman projections
- R and S Configuration of Allenes
- Converting Bond-Line, Newman Projection, and Fischer Projections
- Resolution of Enantiomers: Separate Enantiomers by Converting to Diastereomers
- Stereochemistry Practice Problems
- Stereochemistry Practice Quiz
Energy Changes In Organic Chemistry
Nucleophilic Substitution Reactions
- Introduction to Alkyl Halides
- Nomenclature of Alkyl Halides
- Substitution and Elimination Reactions
- Nucleophilic Substitution Reactions – An Introduction
- All You Need to Know About the SN2 Reaction Mechanism
- The SN2 Mechanism: Kinetics, Thermodynamics, Curved Arrows, and Stereochemistry with Practice Problems
- The Stereochemistry of SN2 Reactions
- Stability of Carbocations
- The SN1 Nucleophilic Substitution Reaction
- Reactions of Alkyl Halides with Water
- The Stereochemistry of the SN1 Reaction Mechanism
- The SN1 Mechanism: Kinetics, Thermodynamics, Curved Arrows, and Stereochemistry with Practice Problems
- Steric Hindrance in SN2 and SN1 Reactions
- Carbocation Rearrangements in SN1 Reactions with Practice Problems
- Ring Expansion Rearrangements
- Ring Contraction Rearrangements
- When Is the Mechanism SN1 or SN2?
- Reactions of Alcohols with HCl, HBr, and HI Acids
- SOCl2 and PBr3 for Conversion of Alcohols to Alkyl Halides
- Alcohols in SN1 and SN2 Reactions
- How to Choose Molecules for Doing SN2 and SN1 Synthesis-Practice Problems
- Exceptions in SN2 and SN1 Reactions
- Nucleophilic Substitution and Elimination Practice Quiz
- Reactions Map of Alkyl Halides
Alkenes: Structure, Stability, and Nomenclature
Elimination Reactions
- Substitution and Elimination Reactions
- The E2 Mechanism
- E2 Elimination Practice Problems
- Zaitsev’s Rule – Regioselectivity of E2 Elimination Reactions
- The Hofmann Elimination of Amines and Alkyl Fluorides
- Stereoselectivity of E2 Elimination Reactions
- Stereospecificity of E2 Elimination Reactions
- SN2 and E2 Rates of Cyclohexanes
- Elimination Reactions of Cyclohexanes with Practice Problems
- POCl3 for Dehydration of Alcohols
- The E1 Mechanism with Practice Problems
- Regioselectivity of E1 Reactions
- Stereoselectivity of E1 Reactions
- How to tell if it is E2 or E1 Mechanism
- SN1 vs E1 Reactions
- SN2 vs E2 Reactions
- Dehydration of Alcohols by E1 and E2 Elimination
- Mesylates and Tosylates as Good Leaving Groups
- Mitsunobu Reaction
- SN1 SN2 E1 E2 – How to Choose the Mechanism
- Polar Protic and Polar Aprotic Solvents
- SN1 SN2 E1 or E2 – the Largest Collection of Practice Problems
- The Hammond Postulate
- The E1cB Elimination Mechanism
- Nucleophilic Substitution and Elimination Practice Quiz
- Reactions Map of Alkyl Halides
Addition Reactions of Alkenes
- Electrophilic Addition Reactions to Alkenes
- Markovnikov’s Rule
- Markovnikov’s Rule with Practice Problems
- Addition of Water to Alkenes
- Acid-Catalyzed Hydration of Alkenes with Practice Problems
- Rearrangements in Alkene Addition Reactions
- Oxymercuration-Demercuration
- Addition of Alcohols to Alkenes
- Free-Radical Addition of HBr: Anti-Markovnikov Addition
- Hydroboration-Oxidation: The Mechanism
- Hydroboration-Oxidation of Alkenes: Regiochemistry and Stereochemistry with Practice Problems
- Halogenation of Alkenes and Halohydrin Formation
- The Regiochemistry of Alkene Addition Reactions
- The Stereochemistry of Alkene Addition Reactions
- Cis product in an anti-Addition Reaction of Alkenes
- Ozonolysis of Alkenes with Practice Problems
- Syn Dihydroxylation of Alkenes with KMnO4 and OsO4
- Anti-Dihydroxylation of Alkenes with MCPBA and Other Peroxides with Practice Problems
- Oxidative Cleavage of Alkenes with KMno4 and O3
- Alkene Reactions Practice Problems
- Changing the Position of a Double Bond
- Changing the Position of a Leaving Group
- Alkenes Multi-Step Synthesis Practice Problems
- Alkene Addition Reactions Practice Quiz
- Reactions Map of Alkenes
Alkynes
- Introduction to Alkynes
- Naming Alkynes by IUPAC Nomenclature Rules – Practice Problems
- Preparation of Alkynes by Elimination Reactions
- Hydrohalogenation of Alkynes
- Addition of Water to Alkynes
- Acid-Catalyzed Hydration of Alkynes with Practice Problems
- Reduction of Alkynes
- Halogenation of Alkynes
- Hydroboration-Oxidation of Alkynes with Practice Problems
- Ozonolysis of Alkynes with Practice Problems
- Alkylation of Terminal Alkynes in Organic Synthesis with Practice Problems
- Reactions of Acetylide Ions
- Alkyne reactions summary practice problems
- Alkyne Synthesis Reactions Practice Problems
- Alkyne Naming and Reactions Practice Quiz
- Reactions Map of Alkynes
Nuclear Magnetic Resonance (NMR) Spectroscopy
- NMR Spectroscopy – An Easy Introduction
- NMR Chemical Shift
- NMR Chemical Shift Range and Value Table
- NMR Number of Signals and Equivalent Protons
- Homotopic, Enantiotopic, Diastereotopic, and Heterotopic
- Homotopic Enantiotopic Diastereotopic Practice Problems
- Integration in NMR Spectroscopy
- Splitting and Multiplicity (N+1 rule) in NMR Spectroscopy
- NMR Signal Splitting N+1 Rule Multiplicity Practice Problems
- 13C Carbon NMR
- DEPT NMR: Signals and Problem Solving
- NMR Spectroscopy-Carbon-Dept-IR Practice Problems
Organic Structure Determination
Radical Reactions
- Free-Radical Addition of HBr: Anti-Markovnikov Addition
- Initiation, Propagation, Termination in Radical Reactions
- Selectivity in Radical Halogenation
- Stability of Radicals
- Resonance Structures of Radicals
- Stereochemistry of Radical Halogenation with Practice Problems
- Allylic Bromination by NBS with Practice Problems
- Radical Halogenation in Organic Synthesis
Reactions of Alcohols
- Nomenclature of Alcohols: Naming Alcohols based on IUPAC Rules with Practice Problems
- Preparation of Alcohols via Substitution or Addition Reactions
- Reaction of Alcohols with HCl, HBr, and HI Acids
- Mesylates and Tosylates as Good Leaving Groups
- SOCl2 and PBr3 for Conversion of Alcohols to Alkyl Halides
- Alcohols in Substitution Reactions Practice Problems
- POCl3 for Dehydration of Alcohols
- Dehydration of Alcohols by E1 and E2 Elimination
- The Oxidation States of Organic Compounds
- LiAlH4 and NaBH4 Carbonyl Reduction Mechanism
- Alcohols from Carbonyl Reductions – Practice Problems
- Grignard Reaction in Preparing Alcohols with Practice Problems
- Grignard Reaction in Organic Synthesis with Practice Problems
- Protecting Groups For Alcohols in Organic Synthesis
- Oxidation of Alcohols: PCC, PDC, CrO3, DMP, Swern, and All of That
- Diols: Nomenclature, Preparation, and Reactions
- NaIO4 Oxidative Cleavage of Diols
- The Pinacol Rearrangement
- The Williamson Ether Synthesis
- Alcohol Reactions Practice Problems
- Naming Thiols and Sulfides
- Reactions of Thiols
- Alcohols Quiz – Naming, Preparation, and Reactions
- Reactions Map of Alcohols
Ethers and Epoxides
Conjugated Systems
The Diels-Alder Reaction
- Diels-Alder Reaction: Dienes and Dienophiles
- Predict the Products of the Diels-Alder Reaction with Practice Problems
- Endo and Exo Products of Diels-Alder Reaction with Practice Problems
- Regiochemistry of the Diels–Alder Reaction with Practice Problems
- Identify the Diene and Dienophile of the Diels-Alder reaction with Practice Problems
- Diels-Alder Reaction in Organic Synthesis Practice Problems
Aromatic Compounds
Electrophilic Aromatic Substitution
- Electrophilic Aromatic Substitution – The Mechanism
- The Halogenation of Benzene
- The Nitration of Benzene
- The Sulfonation of Benzene
- Activating and Deactivating Groups
- Friedel-Crafts Alkylation with Practice Problems
- Friedel-Crafts Acylation with Practice Problems
- Vilsmeier-Haack Reaction
- The Alkylation of Benzene by Acylation-Reduction
- Ortho, Para, Meta in EAS with Practice Problems
- Ortho, Para, and Meta in Disubstituted Benzenes
- Why Are Halogens Ortho-, Para- Directors yet Deactivators?
- Is Phenyl an Ortho/Para or Meta Director?
- Limitations of Electrophilic Aromatic Substitution Reactions
- Orientation in Benzene Rings With More Than One Substituent
- Synthesis of Aromatic Compounds From Benzene
- Arenediazonium Salts in Electrophilic Aromatic Substitution
- Reactions at the Benzylic Position
- Benzylic Bromination
- Nucleophilic Aromatic Substitution
- Nucleophilic Aromatic Substitution Practice Problems
- Reactions of Phenols
- Reactions of Aniline
- Meta Substitution on Activated Aromatic Ring
- Electrophilic Aromatic Substitution Practice Problems
- Aromatic Compounds Quiz
- Reactions Map of Aromatic Compounds
Aldehydes and Ketones
- Nomenclature of Aldehydes and Ketones
- How to Name a Compound with Multiple Functional Groups
- Preparation of Aldehydes and Ketones
- Nucleophilic Addition to Carbonyl Groups
- Reduction of Aldehydes and Ketones
- Reactions of Aldehydes and Ketones with Water
- Reactions of Aldehydes and Ketones with Alcohols: Acetals and Hemiacetals
- Acetals as Protecting Groups for Aldehydes and Ketones
- Formation and Reactions of Imines and Enamines
- Reductive Amination
- Acetal Hydrolysis Mechanism
- Imine and Enamine Hydrolysis Mechanism
- Hydrolysis of Acetals, Imines, and Enamines-Practice Problems
- Reaction of Aldehydes and Ketones with CN, Cyanohydrin Formation
- The Wittig Reaction: Examples and Mechanism
- The Wittig Reaction: Practice Problems
- Aldehydes and Ketones to Carboxylic Acids
- Reactions of Aldehydes and Ketones – Practice Problems
- Aldehydes and Ketones Reactions Practice Quiz
- Reactions Map of Aldehydes
- Reactions Map of Ketones
Carboxylic Acids and Their Derivatives-Nucleophilic Acyl Substitution
- Preparation of Carboxylic Acids
- Naming Carboxylic Acids
- Naming Nitriles
- Naming Esters
- Naming Carboxylic Acid Derivatives – Practice Problems
- The Addition-Elimination Mechanism
- Fischer Esterification
- Ester Hydrolysis by Acid and Base-Catalyzed Hydrolysis
- What is Transesterification?
- Esters Reaction with Amines – The Aminolysis Mechanism
- Ester Reactions Summary and Practice Problems
- Preparation of Acyl (Acid) Chlorides (ROCl)
- Reactions of Acid Chlorides (ROCl) with Nucleophiles
- R2CuLi Organocuprates – Gilman Reagent
- Reaction of Acyl Chlorides with Grignard and Gilman (Organocuprate) Reagents
- Reduction of Acyl Chlorides by LiAlH4, NaBH4, and LiAl(OtBu)3H
- Reduction of Carboxylic Acids and Their Derivatives
- Preparation and Reaction Mechanism of Carboxylic Anhydrides
- Amides – Structure and Reactivity
- Naming Amides
- Amides Hydrolysis: Acid and Base-Catalyzed Mechanism
- Amide Dehydration Mechanism by SOCl2, POCl3, and P2O5
- Amide Reduction Mechanism by LiAlH4
- Reduction of Amides to Amines and Aldehydes
- Amides Preparation and Reactions Summary
- Amides from Carboxylic Acids-DCC and EDC Coupling
- The Mechanism of Nitrile Hydrolysis To Carboxylic Acid
- Nitrile Reduction Mechanism with LiAlH4 and DIBAL to Amine or Aldehyde
- The Mechanism of Grignard and Organolithium Reactions with Nitriles
- The Reactions of Nitriles
- Converting Nitriles to Amides
- Carboxylic Acids to Ketones
- Esters to Ketones
- Carboxylic Acids and Their Derivatives Practice Problems
- Carboxylic Acids and Their Derivatives Quiz
- Reactions Map of Carboxylic Acid Derivatives
Alpha Carbon Chemistry: Enols and Enolates
- Keto-Enol Tautomerization
- Alpha Halogenation of Enols and Enolates
- The Haloform and Iodoform Reactions
- Alpha Halogenation of Carboxylic Acids
- Alpha Halogenation of Enols and Enolates Practice Problems
- The E1cB Elimination Mechanism
- Aldol Reaction – Principles and Mechanism
- Aldol Condensation – Dehydration of Aldol Addition Product
- Intramolecular Aldol Reactions
- Aldol Addition and Condensation Reactions – Practice Problems
- Crossed Aldol And Directed Aldol Reactions
- Crossed Aldol Condensation Practice Problems
- The Cannizzaro reaction
- Alkylation of Enolates Alpha Position
- Enolate Alkylation Practice Problems
- Acetoacetic Ester Synthesis
- Acetoacetic Ester Enolates Practice Problems
- Malonic Ester Synthesis
- Decarboxylation
- Michael Reaction: The Conjugate Addition of Enolates
- Robinson Annulation, Shortcut, and Retrosynthesis
- Claisen Condensation
- Dieckmann condensation – An Intramolecular Claisen Reaction
- Crossed Claisen and Claisen Variation Reactions
- Claisen Condensation Practice Problems
- Stork Enamine Synthesis
- Mannich Reaction
- Enolates in Organic Synthesis – a Comprehensive Practice Problem
Amines
- Naming Amines: Systematic and Common Nomenclature
- Preparation of Amines
- The Gabriel Synthesis of Primary Amines
- Imines from Aldehydes and Ketones with Primary Amines
- Enamines from Aldehydes and Ketones with Secondary Amines
- The Hofmann Elimination of Amines and Alkyl Fluorides
- The Reaction of Amines with Nitrous Acid
- Reactions of Amines Practice Problems
- The Cope elimination
- Basicity of Amines
- Boc Protecting Group for Amines
Organic Synthesis Problems
- Organic Chemistry Multistep Synthesis Practice Problems
- Organic Synthesis Puzzles
- Acetals as Protecting Groups for Aldehydes and Ketones
- How to Choose Molecules for Doing SN2 and SN1 Synthesis-Practice Problems
- Alkene Reactions Practice Problems
- Changing the Position of a Double Bond
- Changing the Position of a Leaving Group
- Alkenes Multi-Step Synthesis Practice Problems
- Alkyne Synthesis Reactions Practice Problems
- Radical Halogenation in Organic Synthesis
- Grignard Reaction in Organic Synthesis with Practice Problems
- Ortho Para Meta in EAS with Practice Problems
- Orientation in Benzene Rings With More Than One Substituent
Carbohydrates
- Carbohydrates – Structure and Classification
- Erythro and Threo
- R and S Configuration on Fischer Projections
- D and L Sugars
- Aldoses and Ketoses: Classification and Stereochemistry
- Epimers and Anomers
- Converting Fischer, Haworth, and Chair forms of Carbohydrates
- Mutarotation
- Glycosides
- Isomerization of Carbohydrates
- Ether and Ester Derivatives of Carbohydrates
- Oxidation of Monosaccharides
- Reduction of Monosaccharides
- Kiliani–Fischer Synthesis
- Wohl Degradation
- Carbohydrates Practice Problem Quiz
Your feedback means a lot, and it helps future students feel confident about joining and enjoying the same benefits, and it inspires me to continue giving my best support.
which one is smallest aromatic compounds benzene or train gul shap with 1 singer bond and one positive charge on it?
You need to explain yourself better. What is train gul shap ?
Nomenclature of Thiols, Ethers, Alkyl Halides, and Others
Can you explain this
Yes, they can be found here, and if you have a specific question, you can ask here or under the comments of these posts.
Hi
I need help with stereoisomers, chiral centres, R and S con figuration
Go ahead, Raphaella
I’m having difficulties finding naming R and S configurations
There are two components there, yes? 1) You need to know the IUPAC rules to name the molecule. 2) You need to be able to determine the R and S configuration. First, name the molecule as if it does not have any chiral centers, then add the configurations of these chiral centers with the corresponding locants, i.e., 4R, 3S. Do you have a specific example? You can draw that on the board.
I face trouble to elucidate structure while reading of HSQC and HMBC . how to elucidate structure from HSQC and HMBC .plz can you guide me how i clear my confusion related the topic in NMR .
I mostly face problem to search mechanism of different organic reactions . is there any website where i can check mechanism of any reaction?
HSQC and HMBC are 2D NMR correlation techniques – HSQC shows direct ¹H–¹³C (one-bond) correlations, while HMBC shows long-range (2-3 bond) H–C correlations. If you already know how to interpret ¹H and ¹³C NMR, using HSQC and HMBC together is usually not very difficult, they mainly help you connect protons to the correct carbons. That said, without a specific spectrum or example, it’s hard to generalize how to solve every case.
As for reaction mechanisms, don’t we all wish there were a website that could draw the mechanism for any reaction 🙂 Unfortunately, chemistry doesn’t quite work that way. However, most common mechanisms and recurring patterns in undergraduate organic chemistry are covered here on Chemistry Steps, as well as on other organic chemistry websites and YouTube channels. Once you learn the patterns, you can usually reason out the mechanism yourself.
Thank you sir for answering. Sir I somehow able to interpret structure of organic compound by taking help from HNMR and C-NMR spectra and some how from Molecular formula .but in our course there is topics of COSY, HSQC ,HMBC .and I get sometimes failed to interpret and elucidate structure and in simple way the use of HSQC and HMBC . how I can read and elucidate any structure . can you plz sir guide me or having any notes etc or recommended video etc. Plz sir I will be much grateful.
Hello Shahana,
Glad to hear you’re making progress with ¹H and ¹³C NMR! As I mentioned before, HSQC and HMBC are just tools to connect protons to the right carbons and reveal longer-range correlations. If you keep practicing with specific examples and spectra, it will gradually become much easier to interpret.
Other than your professor’s notes, you may also want to check out textbooks on organic structure determination and look for additional online materials and videos. Sorry for not being too specific – this is a specialized topic, and I would recommend asking your professor for further guidance to really master it. With practice, reading 2D NMR becomes a natural extension of what you already know from 1D NMR.
Ok sir thank you so much for guidance.