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Created by Jared Mader Pathways and Methodology Created by Jared Mader Chemical Identification The tests found in the identification methods listed below.

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Presentation on theme: "Created by Jared Mader Pathways and Methodology Created by Jared Mader Chemical Identification The tests found in the identification methods listed below."— Presentation transcript:

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2 Created by Jared Mader Pathways and Methodology

3 Created by Jared Mader Chemical Identification The tests found in the identification methods listed below will help you identify the unknown chemicals used by the food manufacturer: –Cation IdentificationCation Identification –Anion IdentificationAnion Identification –ResourcesResources

4 Created by Jared Mader Cation Identification When testing cation, the following methods may be employed: –Chemical Color IdentificationChemical Color Identification –SolubilitySolubility –Flame Test for IdentificationFlame Test for Identification –Addition of sodium hydroxide solutionAddition of sodium hydroxide solution –Addition of ammonia solutionAddition of ammonia solution –Addition of potassium iodide solutionAddition of potassium iodide solution –Ammonium IdentificationAmmonium Identification –Addition of Hydrochloric AcidAddition of Hydrochloric Acid Main

5 Created by Jared Mader Anion Identification When testing anion, the following methods may be employed: –Addition of silver nitrate to a slightly acidic solution of compoundAddition of silver nitrate to a slightly acidic solution of compound –Addition of sulfuric acid*Addition of sulfuric acid* –Polyatomic anion testsPolyatomic anion tests –Addition of Lead(II) NitrateAddition of Lead(II) Nitrate Main

6 Created by Jared Mader Chemical Color Identification Compounds of some transition metals have unique color: –Copper: blue, blue/green –Chromium: green, purplish/green –Iron: pale green, yellow, amethyst –Nickel: green –Cobalt: red Back

7 Created by Jared Mader Solubility The following are insoluble: –Halides of lead and silver –Sulfates of barium, calcium, strontium, and lead –Carbonates of all metals with the exception of alkali metals Back

8 Created by Jared Mader Flame Tests Upon using cue tip dip flame test, color emission will be: –Sodium: bright yellow/orangebright yellow/orange –Potassium: lilac lilac –Strontium/Lithium: bright red –Barium: pale green –Calcium: brick/orange red –Copper: green with blue/white centergreen with blue/white center –Lead: Whitish in color Back

9 Created by Jared Mader Sodium Hydroxide Addition Carefully add dilute NaOH solution to solution of unknown –White precipitate: calcium, zinc, strontium, aluminum, and lead –Blue precipitate, but turns black upon heating: copper –Green precipitate: Nickel –Gray/green, turning brown on standing: Iron(II) –Red precipitate: Iron(III) –Blue precipitate, turning gray upon standing: Cobalt Back

10 Created by Jared Mader Ammonia Solution Addition Carefully add dilute NH 3 solution to solution of unknown –White precipitate: calcium, aluminum, lead, and zinc –Blue precipitate, turning to deep blue solution as more NH 3 is added : copper –Coral Blue Solution: nickel –Gray/green, turning brown on standing: Iron(II) –Red precipitate: Iron(III) –Blue precipitate, turning gray upon standing: Cobalt Back

11 Created by Jared Mader Addition of Potassium Iodide Solution Carefully add dilute KI solution to solution of unknown –Yellow precipitate: lead Back

12 Created by Jared Mader Addition of Potassium Chromate Solution Carefully add dilute potassium chromate solution to solution of unknown –Fine crystalline precipitate: zinc, cobalt, iron(III), nickel, or lead Back

13 Created by Jared Mader Addition of HCl Solution Carefully add dilute HCl solution to solution of unknown –White Precipitate: lead Back

14 Created by Jared Mader Addition of Silver Nitrate Carefully add a dilute AgNO 3 solution to a slightly acidic solution of unknown Create slightly acidic solution by adding several drops of HNO 3 –White precipitate: chloride –Cream precipitate: bromide –Yellow precipitate: iodide Back

15 Created by Jared Mader Addition of Sulfuric Acid *MUST BE CONDUCTED IN FUME HOOD Carefully add several drops of concentrated sulfuric acid to solution of unknown –Brown acidic fumes: bromide or nitrite –Purple acidic fume: iodide Back

16 Created by Jared Mader Addition of Lead(II) Nitrate Carefully add several drops of lead(II) nitrate solution to a solution of unknown –Yellow precipitate: iodide –White precipitate: bromide, chloride or sulfate Back

17 Created by Jared Mader Polyatomic Ion Tests To a solution of the unknown, carefully add several drops of: –COLD NaOH = strong ammonia smell and litmus turns red to blue = ammonium ion –Dilute solution of potassium permanganate and HCl = turns from purple to clear = nitrite ion –Ammonium solution = strong ammonia smell, no precipitate and litmus turns red to blue = hydroxide ion –If soluble, add AlNO 3 solution = white precipitate = hydroxide ion –Heat solid in a test tube with a burner = brown gas(nitrogen dioxide) = nitrate ion [MUST COMPLETE IN FUME HOOD] –HCl and BaCl 2 = white precipitate = sulfate ion –Dilute HCl = vigorous bubbling of CO 2 gas = carbonate ion –Gently heat solid = color change/release of CO 2 = carbonate ion Back

18 Created by Jared Mader Polyatomic Ion Tests To a solution of the unknown, carefully add several drops of: –COLD NaOH = strong ammonia smell and litmus turns red to blue = ammonium ion –Dilute solution of potassium permanganate and HCl = turns from purple to clear = nitrite ion –Ammonium solution = strong ammonia smell, no precipitate and litmus turns red to blue = hydroxide ion –If soluble, add AlNO 3 solution = white precipitate = hydroxide ion –Heat solid in a test tube with a burner = brown gas(nitrogen dioxide) = nitrate ion [MUST COMPLETE IN FUME HOOD] –HCl and BaCl 2 = white precipitate = sulfate ion –Dilute HCl = vigorous bubbling of CO 2 gas = carbonate ion –Gently heat solid = color change/release of CO 2 = carbonate ion Back

19 Created by Jared Mader This Site Made Possible by: on%20tests% htmlhttp://www.rjclarkson.demon.co.uk/middle/Inorganic%20i on%20tests% html micalTests/ChemicalTests.htmhttp://www.wpbschoolhouse.btinternet.co.uk/page13/Che micalTests/ChemicalTests.htm Main


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