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Lab PrepClean beakers and test tubes (make sure small test tubes). | Grab strips of different colored washi tape for labeling. | Grab disposable pipettes. | Fill soap and distilled water. |
Separation of Quall II ions:Separation of Qual II ions done with strong base, NaOH. | Mn 2+, Ni2+, Fe2+. Will precipitate as a Hydroxides. | Al3+ and Zn2+ will precipitate soluble Hydroxides. | Add 2 mL of original solution to small cleaned test tube. (DO NOT USE 2 mL WHEN DOING UNKNOWN) | Add 15 drop of 6M NaOH | Centrifuge and save precipitate and supernate. (Test for incomplete reaction; several drops of 6 M NaOH) | Label supernate "Al & Zn ions". | Dissolve the precipitate with the minimum amount of concentrated Nitric Acid (HNO3) possible. | If necessary heat the solution. | Label dissolved, " Mn, Ni, & Fe ions" |
Testing for Mn 2+ PresenceAdd approximatly 1/2 of "Mn, Ni, & Fe" to a small test tube. (DO NOT USE THAT MUCH IF DOING QUAL II UNKNOWN." | Add solid NaBiO3 in excess to the solution and centrifuge. | Deep purple solution confirms Mn 2+ ion presence. |
Testing for the presence of Fe 3+Add remaining 1/2 solution of "Mn, Ni, & Fe" (DO NOT USE ALL IF DOING QUAL II UNKNOWN" | Excess ammonia does not react with Mn the addition is to make Fe a brown precipitate and Ni a blue supernate. | Add 5 drops of $M NH4Cl to the solution | Add concentrated ammonium hydroxide (NH4OH) till it is basic to litmus. | Add additional three drops to check for reaction completion. | Centerfuge & save supernate label for Ni testing | Dissolve percipitate with 6M HCl | Add 5 drops of 0.1M NH4SCN. Presence of blood red color confirms presence of Fe. |
Testing for Ni PresenceComplexing agent (Dimethylglyoxime) reacting specifically with Ni ions | Using test tube labeled Ni supernate | Appearance of pinkish red precipitate. |
Testing for Al PresenceAddition of acid breaks down Al & Zn Hydroxides to ions | Add HNO3 drop wise to supernated labeled "Zn & Al ions" solution must be basic to litmus paper. | Add 5 more drops after that to insure reaction completion. | Presence of white cloudy percipitate indicated presence of Al ions.` | Centerfuge and save Zn supernate for analysis. |
Testing for Zn percipitateAddition of 6M HCl to supernate Zn+ until solution is acidic to litmus paper | Add 3 drop of 0.2M K4[Fe(CN)6] and stir. | Centrifuge and discard supernate. | Light green precipitate confirms presence of Zn. |
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