IGCSE›Edexcel IGCSE Chemistry›Mind maps4.1 IntroductionEdexcel IGCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsHydrocarbonsContain hydrogen and carbon onlyCarbon forms four covalent bondsBuilds chains, branches and ringsBackbone plus functional groupTypes of formulaEmpirical: simplest ratio, butane is CX2HX5\ce{C2H5}CX2HX5Molecular: actual atoms, CX4HX10\ce{C4H10}CX4HX10General: whole series, CXnHX2n+2\ce{C_nH_{2n+2}}CXnHX2n+2Structural: CHX3CHX2CHX2CHX3\ce{CH3CH2CH2CH3}CHX3CHX2CHX2CHX3Displayed: every bond drawnSeries and isomersHomologous series: same functional groupMembers differ by CH2Physical properties change graduallyIsomers: same molecular formula, different structureCX4HX10\ce{C4H10}CX4HX10: butane and methylpropaneOrganic introhydrocarbons and namingCHCH2NamingStem shows longest chain lengthmeth-, eth-, prop-, but-, pent-, hex-Suffix or prefix shows functional groupReaction typesSubstitution: atom replaced by anotherAddition: two molecules join, nothing lostCombustion: reacts with oxygen, releases heatExam tipsCount the longest chain first for the stem