Doc Brown's Chemistry Clinic

CHEMICAL identification TESTS

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)

 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 * 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 * Gas Preparations *  Hazard warning signs/symbols-examples of labelling

• PLEASE NOTE:

• Where possible balanced symbol equations are given.

• 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 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. 

KS3 SCIENCE * KS4 SCIENCE GCSE IGCSE GCE AS A2 IB CHEMISTRY * SITE PURPOSE EDUCATION - online learning or 'self-private-tuition' using revision notes, quizzes, practice tests involving SCIENCE in the areas of REVISING only the CHEMISTRY-Earth Science-Radioactivity at Doc Brown's Chemistry Clinic via HOMEPAGE in secondary school/schools, 6th form college/colleges, academy/academies or home self-study and may help with 1st year undergraduate university chemistry courses. Hopefully it will encourage interest and understanding of Chemistry, Earth Science and Radioactivity in any country of the world, though the site is written entirely in English. The website is designed to help and unofficially support students/teachers revise-learn/teach the chemistry for modular or co-ordinated examination science courses from UK QCA based AQA, OCR (Oxford and Cambridge) Twenty First Century (21st C) and Gateway Science, Edexcel 360Science (Additional/Applied 360 science) , Nuffield, Salters, Cambridge International (CIE), London International, WJEC, CCEA exams etc. Also, national award assessments-examinations for GCSE-IGCSE-KS4-O level-BTEC-NVQ applied, additional and chemistry science courses and examinations, Advanced Subsidiary Level GCE-AS-A2-IB-KS5-BTEC-NVQ National Chemistry assessment levels, KS3 SATs Science-biology/chemistry/physics (SAT revision levels 3-5 or 5-7) and covers much of the revising, learning and teaching chemistry of the International Baccalaureate, K12 US grade 6,7,8,9,10,11,12,AP basic level examinations courses for the national curriculum for secondary schools and colleges. The site does not support the content of England, Wales or Northern Ireland primary science KS1 or KS2. The notes should also provide some background theory for a coursework assignment or a project. Please note that my on-line revision notes and quizzes are no substitute for good classroom teaching-lecturing and thorough studying of your own notes and textbooks, practicing past papers and a copy of the syllabus which are readily downloaded from the examination board sites, but I hope here and there they will lend a tutoring hand on some topic, unit, module etc. (© Dr W P Brown 14-12-07]

Online free help resources for Key Stages 3 SATs (S.A.T.s), 4 & 5AQA, Edexcel, OCR, CIE GCSE IGCSE BTEC Science, GCE, AS, A2 Advanced subsidiary Chemistry A levels, IB Diploma and US K12 (K-12 grades) courses and examinations and revising for the various syllabuses and specifications. Exploring the site for lessons, plans, ideas for projects and coursework, professional development. Through hard work the site has been built up over the course of many years with no need of special pc software except FrontPage and Hot Potatoes (uvic) for quizzes and worksheets. It is used in the classroom, home learning-tutoring-schooling and guidance, private tuition, school retakes revision. Whether you are a teacher/tutor teaching, a student studying, using the pages as self-study guides for your science-chemistry studies etc. etc. I hope the site supports your endeavour. 15-12-07 © Dr W P Brown