GCSE›AQA GCSE Chemistry›Mind mapsIdentification of Common GasesAQA GCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsHydrogenLit burning splint at the tube mouthSqueaky pop heard2 HX2+OX2→2 HX2O\ce{2H2 + O2 -> 2H2O}2HX2+OX22HX2OMade by metal + dilute acidOxygenGlowing splint into the gasSplint relightsOxygen supports combustionMade by HX2OX2\ce{H2O2}HX2OX2 with MnOX2\ce{MnO2}MnOX2 catalystGas testsidentifying common gasesH2O2CO2Cl2Carbon dioxideBubble through limewaterTurns milkyForms insoluble calcium carbonateCa(OH)X2+COX2→CaCOX3+HX2O\ce{Ca(OH)2 + CO2 -> CaCO3 + H2O}Ca(OH)X2+COX2CaCOX3+HX2OChlorineDamp litmus paperPaper bleaches whiteToxic: use a fume hoodPale yellow-green gasExam tipsUse exact words: squeaky pop, relights, turns milkyOxygen splint must be glowing, not burningLitmus must be dampSay limewater, not lime solution