Doc Brown's Chemistry  Qualitative Analysis Methods Revision Notes

Part 1 Qualitative tests to identify inorganic gases & ions (cations/anions) and organic molecule functional groups

 Part 1 Introduction - alphabetical list (this page)

 Part 2 Qualitative tests to identify organic molecule functional groups of homologous series

 Part 3 Metal cations (positive ions), metal carbonates, ammonium ion, hydrogen ions (acids)

 Part 4 Gases, water and non-metallic elements

 Part 5 Anions (negative ions) including hydroxide (alkalis)

GCSE/IGCSE Revision Qualitative Analysis Quiz on chemical test methods for identifying ions, gases and compounds

Quantitative analysis: acid-base, silver nitrate-chloride and EDTA titrations * Quantitative analysis: Redox titrations

 Part 1 Test Index and Introduction

Full list of KEYWORDS for inorganic/organic identification methods in alphabetical order e.g. test/reagent for: * acid ==> H⁺ * acid/acyl chloride RCOCl * alcohols - general ROH/prim RCH₂OH/sec R₂CHOH/tert R₃COH) * aldehyde RCHO * prim aliphatic amine R-NH₂ * aliphatic/aromatic carboxylic acids * alkali ==> OH^- * alkane/alkene >C=C</alkyne -CC- (saturated versus unsaturated) * aluminium/aluminum ion Al³⁺ * amide RCONH₂ * prim aliphatic amines R-NH₂ * ammonia gas NH₃ * ammonium ion NH₄⁺ * prim aromatic amine C₆H₅-NH₂ etc. * barium ion Ba²⁺ * Benedict's solution * Brady's reagent * bromide ion Br^- * bromine Br₂ * caesium ion Cs⁺ * calcium ion Ca²⁺ by flame or hydroxide ppt. * carbonate CO₃^2-/hydrogencarbonate HCO₃^- with acid or effect of heating metal carbonate e.g. MCO₃ * carbon dioxide gas CO₂ * carboxylic acid RCOOH * carboxylic acid (aliphatic) salts e.g. RCOO^-Na⁺ * chloride ion Cl^- * chlorine gas Cl₂ * Chomate(VI) ion CrO₄^2- * copper(II) ion Cu²⁺ by flame or hydroxide ppt. * 24DNPH (for aldehydes/ketones test) * esters RCOOR * Fehlings test/solution * flame test for metal ions * fluoride ion F^- * haloalkanes/halogenoalkanes R-X * hydrogen gas H₂ * hydrogen sulphide H₂S * hydrogen ion, acids H⁺ * hydrogen bromide gas/hydrobromic acid HBr * hydrogen chloride gas/hydrochloric acid HCl * hydrogen iodide gas/hydriodic acid HI * hydroxide ion, alkali OH^- * hydroxy/alcohol/phenol (organic) * iodide ion I^- * iodine I₂ * iodoform test - formation of CHI₃ * iron(II) ion Fe²⁺ * iron(III) ion Fe³⁺ * ketone R₂C=O * lead(II) ion Pb²⁺ * lithium ion Li⁺ * lime water Ca(OH)_2(aq) * magnesium ion Mg²⁺ * metal carbonates-heating e.g. MCO₃ * metal ions via hydroxide precipitate * nitrate or nitrate(V) NO₃^- * nitrite or nitrate(III) NO₂^- * nitrogen dioxide or nitrogen(IV) oxide NO₂ * oxygen gas O₂ * phenols C₆H₅OH etc. * potassium ion K⁺ * rubidium ion Rb⁺ * reducing sugars * saturated/unsaturated * silver nitrate AgNO₃ (see chloride, bromide, iodide tests) * sugars (reducing) * sodium ion Na⁺ * strontium Sr⁺ * 'sulphate/sulfate' or sulphate(VI) SO₄^2- * sulphide S^2- * 'sulphite/sulfite' or sulphate(IV) SO₃^2- * sulphur dioxide gas SO₂ * Tollen's Reagent * unsaturated/saturated * water H₂O * zinc ion Zn²⁺ *

Use the alphabetical test list above for identifying anions, cations, gases, molecules etc. to find what you require! for your KS3-KS4 Science-GCSE-IGCSE- Chemistry and AS-A2-IB-US grades 9-12 K12 advanced subsidiary chemistry course etc. and help you to identify unknown inorganic and organic compounds-molecules for qualitative analysis. Its also a good idea to read the brief notes after the alphabetical list.

EMAIL query?comment?test missing? * Gas Preparations *  Hazard warning signs/symbols-examples of labelling

• PLEASE NOTE:

• Most of the tests describe use simple apparatus like test tubes, teat pipette, wire for flame test (nichrome, platinum best but costly) and standard chemical reagents accessible in most school or college laboratories.

• Where possible balanced symbol equations are given for the reactions occurring in doing the test.

• Sometimes a precipitate (ppt) initially forms with a limited amount of a reagent, it may then dissolve in excess of reagent to give a clear solution. Both observations will be crucial for a positive id.

• There are no tests specific to identify a compound e.g.

  • (i) there is no test for calcium chloride, but there are tests for the calcium ion and the chloride ion, i.e. using specific ion tests.

  • (ii) Similarly, in organic tests, all you can do is identify a functional group i.e. a particular bit of the molecular structure of a member of a homologous series, rather a particular unique molecule.

  • Not all the reactions are good definitive tests, but they may well be important reactions of cations or anions you need to know about.

• The first tests in the 'inorganic' section are typical of GCSE Science level, but finally these overlap and extend into those needed for GCE Advanced AS or A2 level. In the organic section, only the alkene test is in GCSE double award science, but some others might be found in a full single or co-ordinated triple award GCSE syllabus. 

• If any GCSE/IGCSE/GCE/AS/A2/IB/US grade 8-12 K12 test seems missing, just let me know by email.

• These days more emphasis is given to modern spectroscopic methods of analysis such as NMR, Infrared, Mass spectrometry, Atomic Emission etc.  Quite correctly, though updating A level chemistry is intellectually challenging at times, it isn't always as much fun!

• The methods described give no recipe details or risk assessment, just basically what is needed, what you see and what you can or cannot deduce. Consult teacher, 'practical' text books and Hazcards before attempting any analysis.

• Most tests involve 'standard' chemical reactions and few tests are totally specific so observations should be viewed in context, i.e. is this a realistic deduction in that particular situation? 

• Please remember each syllabus has its own 'list' of required tests - so do not 'over learn' - check out what is needed!

• There is a web page covering the methods some safety aspects of "Preparing and collecting gases".

• Use the alphabetical list to find the test you need.

A brief description of what the hazard might be.

Biohazard: Biohazardous materials include anything that may cause disease in  living organisms or cause significant impact to the environment or community.

NEW SECTION currently working on the table of examples below. 

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