What is Organic Chemistry?
Organic chemistry is the study of carbon-based compounds — from the methane in natural gas to the DNA in your cells. Carbon's ability to form four stable bonds and link into chains, branches and rings creates an enormous diversity of molecules.
Organic chemistry is the branch of chemistry that studies compounds containing carbon (usually bonded to hydrogen, oxygen, nitrogen or halogens), focusing on their structure, properties, and reactions.
- •Only single C–C bonds
- •General formula CnH2n+2
- •Relatively unreactive (combustion, substitution)
- •Example: methane CH4, ethane C2H6
- •Contain a C=C double or C≡C triple bond
- •General formula CnH2n (alkenes) or CnH2n−2 (alkynes)
- •More reactive — undergo addition reactions
- •Example: ethene C2H4, ethyne C2H2
Step-by-step worked examples
Name the compound CH3–CH2–CH3.
It has 3 carbons in a chain, all connected by single bonds → it's an alkane Suffix is '-ane'; the prefix for 3 carbons is 'prop-' Name: propane
Identify the functional group in CH3–CH2–OH (ethanol).
The –OH group attached to the carbon chain is a hydroxyl group Compounds containing –OH are classified as alcohols Ethanol is a 2-carbon alcohol
Classify C2H4 as saturated or unsaturated, and explain why.
C2H4 fits the formula CnH2n with n = 2 This matches the alkene pattern, which contains one C=C double bond Therefore C2H4 (ethene) is unsaturated
Flashcards
Quick quiz
Q1.What is the general formula for alkanes?
Q2.Which functional group defines alcohols?
Q3.A triple bond between carbon atoms is found in:
Q4.Two compounds with the same molecular formula but different structures are called:
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Common mistakes
All organic compounds contain only carbon and hydrogen. — Correct: Organic compounds are carbon-based but often include oxygen, nitrogen, sulfur, or halogens too — only pure C-H compounds are hydrocarbons.
Alkanes and alkenes with the same carbon count share the same formula. — Correct: They differ: alkanes are CnH2n+2 and alkenes are CnH2n — each degree of unsaturation removes two hydrogens.
Functional groups don't affect a molecule's reactivity. — Correct: Functional groups are exactly what determine a molecule's characteristic chemical reactions.
Isomers are just the same compound with a different name. — Correct: Isomers are genuinely different compounds — same molecular formula, but different structure and often different properties.
FAQ
What is organic chemistry?
It's the branch of chemistry focused on carbon-containing compounds, their structure, properties, and reactions.
What are the basics of organic chemistry (formulas)?
Hydrocarbons follow formulas like CnH2n+2 (alkanes), CnH2n (alkenes), and CnH2n−2 (alkynes), based on their bonding.
How do you identify a functional group in organic chemistry?
Look for a distinctive atom group — like –OH (alcohol), –COOH (carboxylic acid), or C=C (alkene) — attached to the carbon backbone.
What are examples of organic chemistry in everyday life?
Fuels, plastics, medicines, and the food we eat are all built from organic compounds.