Unsaturated Hydrocarbon
An unsaturated hydrocarbon is a hydrocarbon that contains at least one double bond or triple bond between carbon atoms.
Practice This ConceptMain explanation
Teacher explanation
Unsaturated hydrocarbons are more reactive than saturated hydrocarbons because double and triple bonds can open up for addition reactions. Ethene and ethyne are common examples. In school tests, unsaturation is often checked using bromine water or alkaline potassium permanganate, which get decolourised by such compounds.
Example
Ethene, C2H4, is an unsaturated hydrocarbon because it contains a carbon-carbon double bond.
Simple analogy
Double or triple bond means unsaturated.
Common confusion
Students often think any hydrocarbon with many hydrogens is saturated. The actual bond pattern must be checked first.
Exam tip
Look for C=C or C≡C. If either is present, the hydrocarbon is unsaturated.
Study the unsaturated hydrocarbon diagram carefully
Use the labelled diagram to keep unsaturated hydrocarbon clear in short answers and revision.
What this diagram makes clear
This diagram keeps the labels and direction of unsaturated hydrocarbon in the right order.
Where this helps in exams
Use this for labelled diagram work and short exam answers on unsaturated hydrocarbon.
Revision cue
Revise unsaturated hydrocarbon through the labels before writing the answer.
Answer writing and exam use
1-mark use
Write the exact meaning of unsaturated hydrocarbon in one clean line.
2-mark use
Define unsaturated hydrocarbon and add one example or condition.
3-mark use
Explain unsaturated hydrocarbon, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.
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