جداسازی کاتیون های گروه ۴

جداسازی کاتیون های گروه ۴

اسلاید 1: Group IV Cation Analysis جداسازی کاتیون های گروه 4Valdosta State UniversityPurposeهدفTo determine which group IV ions are present in an unknown solution.مقصود ما این است که کاتیون های گروه 4 موجود در یک محلول مجهول را شناسایی کنیم

اسلاید 2: Valdosta State UniversityBackgroundFor this experiment,we need the group IV ions that are: Na+, K+, Ba2+, Ca2+, Mg2+.برای این آزمایش ما به کاتیون های گروه 4 نیاز داریم که عبارت اند از سدیم،پتاسیم،باریم،کلسیم،منیزیمThese are ions which are left after groups I – III have precipitated.یون های گروه 4 که در سمت چپ بعد از گروه یک تا 3 هستند رسوب میدهند

اسلاید 3: Valdosta State UniversityBackground – Group IV Separation Scheme نقشه جداسازی کاتیون های گروه 4

اسلاید 4: Valdosta State UniversityGroup IV UnknownFlame Test K+ lavender flameFlame Test Na+orange-yellow flameA – Flame test for Na+ and K+تست شعله برای شناسایی سدیم و پتاسیممحلولی از نمک های سدیم و پتاسیم نات معلوم در اختیار داریم یک روش برای تععین وجود این یون ها آزمون شعله است

اسلاید 5: Valdosta State UniversityKHC2H3O2,K2CrO4BaCrO4 yellow ppt.Ba2+6M HClFlame Test apple - greenBaSO4 white ppt.6M H2SO4B – Test for Ba2+The formation of a yellow precipitate on the addition of potassium chromate indicates the presence of the barium ion.با اضافه کردن پتاسیم کرومات رسوب زرد رنگی تشکیل میشود که نشان دهنده وجود یون باریم است.Ba2+(aq) + K2CrO4(aq)  BaCrO4(s) + 2K+(aq)

اسلاید 6: Valdosta State UniversityA flame test (apple green) is used to confirm the presence of the ion.تست شعله که به رنگ سیب سبزرنگ درمی آید برای تائید وجود این یون به کار میرود.Ba2+(aq) + H2SO4(aq)  BaSO4(s) + 2H+(aq)تست نهایی برای باریم نوعی رسوب سفید رنگ است که با اضافه کردن محلولی از سولفات به دست می آید

اسلاید 7: Valdosta State UniversityCa2+, Mg2+CaC2O4(NH4)2C2O4Mg2+Flame test red-orange6M HClC – Test for Ca2+The calcium ion is separated from magnesium by precipitating calcium oxalate.Ca2+(aq) + (NH4)2C2O4(aq) CaC2O4(s) + 2NH4+(aq)

اسلاید 8: Valdosta State UniversityValdosta State UniversityC – Test for Ca2+A flame test (red-orange flame) is used to confirm the presence of the calcium ion.Ca2+, Mg2+CaC2O4(NH4)2C2O4Mg2+Flame test red-orange6M HCl

اسلاید 9: Valdosta State UniversityValdosta State UniversityC – Test for Mg2+The magnesium ion is precipitated as a white solid (ammonium phosphate) in an alkaline solution.Ca2+, Mg2+CaC2O4K2C2O4Mg2+Flame test red-orange6M HClMg2+(aq) + NH3(aq) + HPO42-(aq)  MgNH4PO4(s)MgNH4PO4–6H2O white ppt.NH3(aq)Na2HPO4(aq)

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اسلاید 12: Procedure – Experiment 12- For this experiment, work individually.

اسلاید 13: Procedure – Group IV Separation SchemeValdosta State UniversityA – Flame test for Na+ and K+Heat 2 mL of a Group IV cation known or unknown in an evaporating dish until a moist residue remains. Add 20 drops of 6 M HCl to this moist residue, and again heat in the evaporating dish until a moist residue remains. While the moist residue cools, obtain a piece of Nichrome wire and make a small loop in the end of the wire. Clean the wire by dipping the loop in concentrated (12 M) HCl, and inserting the wire into the hottest part of the flame. Keep the wire in the flame until the wire imparts no color to the flame. Group IV UnknownFlame Test Na+orange-yellow flameFlame Test K+ lavender flame

اسلاید 14: Procedure – Group IV Separation SchemeValdosta State UniversityA – Flame test for Na+ and K+Dip the loop of the wire in the moist residue. Place the loop of the wire in the flame and observe the color of the flame. A brilliant orange-yellow flame that persists is a positive test for sodium ion.Clean the wire (steps 4, 5) Dip the wire into the moist residue, and insert the loop end of the wire into the hottest part of the flame. Observe the flame through a cobalt blue filter. A lavender flame observed through the cobalt blue filter confirms potassium ionGroup IV UnknownFlame Test Na+orange-yellow flameFlame Test K+ lavender flame

اسلاید 15: Procedure – Group IV Separation SchemeValdosta State UniversityB – Test for Ba2+Obtain 2 mL of fresh Group IV cation known (or unknown) solution in a medium test tube and add 2 drops of 2 M NH4C2H3O2 and 1 drop of 6 M HC2H3O2.Add 1 drop of 1 M K2CrO4 to the sample.A yellow precipitate means that barium ion is likely to be present. Centrifuge the solution and decant. Save the decantate for Part C.HC2H3O2,K2CrO4BaCrO4 yellow ppt.Ba2+6M HClFlame Test apple - greenBaSO4 white ppt.6M H2SO4

اسلاید 16: Procedure – Group IV Separation SchemeValdosta State UniversityB – Test for Ba2+To the precipitate, add 6 M HCl dropwise until the precipitate dissolves, then add 10 more drops. Transfer 5 drops of the solution to an evaporating dish, and heat until a moist residue remains. Perform a flame test on the moist residue.A weak, apple-green flame is also an indication that barium ion is present. To the remainder of the solution, add 10 drops 6 M H2SO4. A white precipitate also indicates barium ion.HC2H3O2,K2CrO4BaCrO4 yellow ppt.Ba2+6M HClFlame Test apple - greenBaSO4 white ppt.6M H2SO4

اسلاید 17: Procedure – Group IV Separation SchemeValdosta State UniversityC – Test for Ca2+Add 6 M NH3 to the supernatant from Part B until the solution is basic to litmus. Add 10 drops of saturated (NH4)2C2O4 and stir. A white precipitate indicates the presence of calcium ion. If no precipitate appears immediately, warm the solution in a water bath. If a precipitate forms, centrifuge and decant. Save the decantate for Part D.Ca2+, Mg2+CaC2O4(NH4)2C2O4Mg2+Flame test red-orange6M HCl

اسلاید 18: Procedure – Group IV Separation SchemeValdosta State UniversityC – Test for Ca2+Add 6 M HCl to the white precipitate until it dissolves, then add 10 more drops.Transfer the solution to an evaporating dish and heat until a moist residue remains.Perform a flame test on the moist residue,A fleeting red-orange flame is an indication that calcium is present.Ca2+, Mg2+CaC2O4(NH4)2C2O4Mg2+Flame test red-orange6M HCl

اسلاید 19: Procedure – Group IV Separation SchemeValdosta State UniversityD – Test for Mg2+If the decantate from Part C is not basic, add 6 M NH3 until the solution is basic to litmus, then add 5 drops more. Add 10 drops 1 M Na2HPO4 and set the solution aside for approximately ten minutes. A white, crystalline precipitate of MgNH4PO4 (looks like snow) confirms the presence of magnesium.Ca2+, Mg2+CaC2O4(NH4)2C2O4Mg2+Flame test red-orange6M HClMgNH4PO4–6H2O white ppt.NH3(aq)Na2HPO4(aq)

اسلاید 20: SafetyValdosta State UniversityConcentrated HCl causes severe burns to the skin which can take weeks to completely heal and also can cause serious eye damage. This chemical also destroys books and clothing. If you get any on you, wash the affected area(s) with copious quantities of water for ten minutes. Other 6 M acids can cause burns. If you spill some on your skin, wash the affected area with water for five minutes.

اسلاید 21: Waste DisposalBecause the solutions used in this experiment contain ions that can hazardous to the environment and to human health, all solutions and precipitates used in this experiment must be placed in the container marked Recovered Metals and Metal Ions.Valdosta State University