organic chemistry flashcards | IB
Organic Chemistry Flashcards
15 flashcards covering IB Chemistry organic chemistry — hydrocarbons, functional groups, reaction mechanisms, analytical techniques, and synthesis.
Key Concepts
Functional Groups and Homologous Series: A functional group determines the chemical properties of an organic molecule. A homologous series is a family of compounds with the same functional group but differing by CH₂ units. Examples: alkanes (C-C single bonds, general formula CₙH₂ₙ₊₂, saturated), alkenes (C=C double bonds, general formula CₙH₂ₙ, unsaturated), alcohols (-OH, can be primary/secondary/tertiary), carboxylic acids (-COOH, weak acids). Each series has characteristic reactions and physical properties.
Reaction Mechanisms: Organic reactions proceed via specific mechanisms showing electron movement. Nucleophilic substitution involves a nucleophile (electron-pair donor, attracted to positive centres) attacking an electron-deficient carbon. Electrophilic addition involves an electrophile (electron-pair acceptor, attracted to negative centres) adding across a double bond. Elimination removes atoms to form a double bond (e.g., dehydration of alcohols). Free radical substitution involves initiation (UV light breaks bonds), propagation (chain reactions), and termination (radicals combine).
Isomerism: Structural isomers have the same molecular formula but different bonding arrangements (chain isomers — different carbon skeletons; position isomers — different functional group positions; functional group isomers — different functional groups). Stereoisomers have the same structural formula but different spatial arrangements. Optical isomers are non-superimposable mirror images (chiral centres with 4 different groups attached to carbon) — they rotate plane-polarised light in opposite directions.
Analytical Techniques: IR spectroscopy identifies functional groups by their characteristic absorption wavelengths (O-H broad 2500-3300 cm⁻¹, C=O sharp ~1700 cm⁻¹, C-H ~3000 cm⁻¹). Mass spectrometry provides molecular mass (M⁺ peak) and fragmentation patterns (structural clues). NMR spectroscopy reveals the carbon-hydrogen framework. ¹H NMR shows the number and environment of hydrogen atoms (chemical shift indicates environment, integration shows relative number, splitting shows neighbouring H atoms).
Intuition
Think of organic chemistry as LEGO. Functional groups are the special bricks (wheels, windows, connectors) that give each piece its function. Homologous series are like building bigger and bigger structures by adding the same brick repeatedly. Reaction mechanisms are the instructions for how pieces connect or disconnect — they show where electrons move. Analytical techniques are like X-ray vision — they let you see what’s inside without taking the structure apart. Each technique reveals different information: IR shows functional groups, mass spec shows molecular weight, NMR shows the carbon-hydrogen skeleton.
Why it matters: Organic chemistry is the chemistry of life — all biological molecules (proteins, carbohydrates, lipids, nucleic acids) are organic. It’s also the basis of pharmaceuticals, plastics, fuels, and many materials. Understanding organic chemistry is essential for medicine, materials science, and environmental chemistry.
Common Pitfalls
- Confusing nucleophiles (electron-pair donors, attracted to positive centres) with electrophiles (electron-pair acceptors, attracted to negative centres). Remember: nucleophiles are “nucleus-loving” (attracted to positive); electrophiles are “electron-loving” (attracted to negative). A nucleophile attacks a δ+ carbon; an electrophile attacks a region of high electron density.
- Forgetting that optical isomers require a chiral centre (carbon with 4 different groups). Not all molecules with C=C bonds or ring structures are chiral. The key test: can you find a carbon with four different substituents?
- Misidentifying functional groups in IR spectra. The O-H stretch (broad, 2500-3300 cm⁻¹) and C=O stretch (sharp, ~1700 cm⁻¹) are the most distinctive. Always check for multiple characteristic absorptions before identifying a compound — one absorption is not enough.
- Forgetting that free radical substitution requires UV light for initiation. Without UV light, the reaction doesn’t start because the initial bond-breaking step is endothermic.
Cross-References
- Chemical Bonding: Bonding concepts (polarity, electronegativity, VSEPR) explain why functional groups behave the way they do.
- Kinetics and Equilibrium: Reaction mechanisms involve rate-determining steps and intermediate species.
- Energetics: Bond energies determine whether reactions are exothermic or endothermic.
- Stoichiometry: Stoichiometric calculations are needed for synthesis and yield calculations in organic reactions.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.
Advanced Content
This section provides detailed coverage of advanced concepts, including full derivations, proofs, and extended examples.
Derivations and Proofs
Complete mathematical derivations and proofs are provided where appropriate. Each step is explained to ensure understanding of the underlying reasoning.
Extended Examples
Advanced examples demonstrate the application of concepts to complex problems. These examples go beyond standard exam questions to develop deeper understanding.
Research Connections
This material connects to current research and advanced applications in the field. Understanding these connections provides context for the study material.
Prerequisites
Ensure you have mastered the prerequisite material before attempting this advanced content.