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en lons es 6. Add 10 drops of 0.5M copper (II) sulfate, CuSO, to well #A5 (without the indicator). Stir the solution. Record on the Report Form (6a) the formula for the ion furnished by CuSO, that affects the concentration of a species in the equilibrium in Step 2c. Record the color of the solution in well #A5 on the Report Form (6b). Use the equilibrium equation from Step 2c and equation 4 to explain how the formation of the tetraamminecopper(II) ion, [Cu(NH₂), affects the reaction in the equation from step 2c on the Report Form (6c). Write the equation for the favored direction in step 2b-forward or reverse-on the Report Form (6d). 7. Clean and shake dry the well plate and six micropipets. Use a dif- ferent micropipet for each solution. 8. Add 10 mL of water to a small beaker and 2 drops of water to well #A1. Shake out the micropipet and use it to add 20 drops of 0.2 M iron (III) chloride, FeCl,, to the water in the beaker and stir. Record the color on the Report Form (8a). Write the equilibrium reaction involved in this step (8b). 9. Transfer 15 drops of the solution from Step 8 to each of six wells, #A1, #A2, #A3, #A4, #A5, and #A6. Well #A1 will be the standard of com- parison for the colored species formed in the equation written in Step 8b. Save the remaining FeCl, solution for Step 19. 10. Add two drops of 0.2 M iron (III) nitrate, Fe(NO3), to well #A2. Stir well. Describe on the Report Form (10a) the color changes that you observe. Describe on the Report Form (10b) how the concentrations of C and [FeCl changed when Fe(NO3), was added. 11. Add two drops of 1.0 M sodium chloride, NaCl, to well #A3. Stir well. Describe on the Report Form (11a) the color changes that you observe in well #A3. Describe on the Report Form (11b) how the concentrations of Fe and [FeCl change when NaCl is added. 12. Add two drops of 0.2 M potassium thiocyanate, KSCN, to well #A4. Stir well. Record on the Report Form (12a) the color changes that you observe. Describe on the Report Form (12b) how the concentrations of Fe, CI, and [FeCll change when KSCN is added. Get help from your instructor for an explanation of which species is the most stable, [FeCl₂] or [Fe(SCN)2+ (Report Form (12c)). 13. Add two drops of saturated solution of sodium fluoride, NaF, to well #A5. Stir well. Record on the Report Form (13a) the color changes- that you observe. Describe on the Report Form (13b) how the con- centrations of Fe", CI", and [FeCll change when NaF is added. Get help from your instructor for an explanation of which species is the most stable, [FeCl] or [FeF (Report Form (13c)).

[Fe(SCN) [FeF, Figure 1 K,[Fe(CN), 14. Add two drops of 0.2 M potassium hexacyanoferrate (II), to well #A6. Stir well. Record on the Report Form (14a) the color changes that you observe. Describe on the Report Form (14b) how the concentrations of Fe", Cl, and [FeCl change. when K[Fe(CN)al is added. Get help from your instructor for an explanation of which species is the most stable, [FeCld or FeFe(CN)als (Report Form (14c)). 15. Clean and shake dry the 24-well plate and four micropipets. Use a different pipet for each solution. 16. Add 50 drops of FeCl, solution from Step 8 to each of the wells #A6, #B6, and #C6. 17. To well #A6, add two drops of 0.2 M KSCN and 15 drops of H₂O. Mix and add 15 drops of this complex solution. [Fe(SCN), to each of three wells, #A1, A2, and #A3. (Note: See the diagram of the well plate below.) 18. To well #B6, add two drops of saturated NaF solution and 15 drops of H₂O. Mix and add 15 drops of this complex solution, [FeF, to each of three wells, #B1, #B2, and #B3. 19. To well #C6, add two drops of 0.2 M K[Fe(CN), and 15 drops of H₂O. Mix and add 15 drops of this complex suspension, Fe[Fe(CN)als, to each of three wells, #C1, C2, and #C3. 20. Add two drops of 0.2 M KSCN to wells #B2 and #C3. Record the final color of the solution in each well on the Report Form (20a). On the Report Form (20b), with help from your instructor, choose which species is most stable. 21. Add two drops of saturated NaF to wells #A2 and #C2. Record the final color of the solution in each well on your Report Form (21a). On the Report Form (21b), with help from your instructor, choose which species is most stable. Fe.[Fe(CN). C A NAF BKSCN) * Nal (SCN) OOO add K₁[Fe(CN) to well A3 add Ka[Fe(CN) to well 83

2011, 2009 Cengage Learning C. Equilibrium between a Solid and Its lons In Solution D. Equilibrium of the Tetraamminecopper(II) Complex Ion, [Cu(NH3)4]²+ 22. Add two drops of 0.2 M K[Fe(CN), to wells #A3 and #83. Record the final color of the solution in each well on your Report Form (22a). On the Report Form (22b), with help from your instructor, choose which species is most stable. 23. List the complexes and compounds with help from your instructor, on your Report Form (23) in order of increasing stability: [FeF, [Fe(SCN)], Fe,[Fe(CN) [FeCl". 24. Clean and shake dry the 24-well plate and three micropipets. Use a different pipet for each solution. 25. Place 10 drops of 0.2 M Pb(NO₂), in well #A1 of the well plate. While stirring constantly, add one drop at a time of 8 M NaOH until four or five drops have been added. Record your observation on your Report Form (25a). On your Report Form (25b), write the equilibrium equa- tion for the reaction of lead (II) ions and hydroxide ions. 26. While stirring constantly, add one drop at a time of 6 M HNO, until 10-15 drops have been added. Record your observation on your Report Form (26a). On your Report Form (26b), explain how the addition of H(aq) ions affects the reaction in the equation you wrote in Step (25b). NOTE: (Recall that OH(aq) + H(aq)-H₂O(0) Write the equation for the favored direction-forward or reverse-on your Report Form (26c). 27. Clean and shake dry the 24-well plate and three micropipets. Use a different pipet for each solution. 28. Add 20 drops of 0.5 M Cu(NO₂)₂ to each of two wells in your well plate, #A1 and #A2. Use well #A1 as the reference for color of the Cu²+ ion. 29. Add 15 drops of 6 M aqueous NH, to well #A2 in your test plate. On the Report Form (29a), compare the color with the reference color of the Cu²+ ion in well #A1. This is the color of the tetraamminecopper(II) complex ion. On the Report Form (29b), write the equilibrium equation for the formation of the tetraammine- copper(II) complex ion from Cu² and NH,. 30. Add drops of 6 M aqueous HNO, to well #A2 until the color appears the same as in reference well #A1 (not to exceed 20 drops). On your Report Form (30), use the equilibrium equation you wrote in Step 29b to explain these results. NOTE: (H(aq) + OH(aq) + H₂O() and NH₂ (aq) + H₂O() NH₂(aq) + OH(aq).)

B. Equilibrium between Ions and Their Complexes color Colorless equilibrium equation fe color change Yellow Step 106. Concentration goes down. [FeCLI- Concentration goes up Step 10a. color change fo Change Step 8a. Step 8b. Step 11a. Step 11b. Fe [FeClal= Step 12a. color change dark blue Step 12b. Fe CI™ [FeCl]". Step 12c. more stable species Step 13a. color change lighter foggy color Step 13b. [Fe]. [CI] [FCL)" Step 13c. more stable species. Step 14a. color change dark red Step 14b. Fe CI™ [FeCh Step 14c. more stable species Step 20. #B2 Step 21. Well Color(a) Step 23. #C3 shrn blue #A2 Vellow #C2 daly blue Step 22. #A3 light rad 1+ 401 can) = [fell₂ ] 0₁ Most stable [FeF]³- [Fe, [Fe(CN)] [Fe(SCN)]2+ [Fe [Fe(CN),l] [Fe(SCN)]²+ [FeF]³- Choice or less stable species. or or or or or less stable species less stable species [Fe(SCN)]2+ [Fe(SCN)]2+ [FeF - [FeF1³- Fe[Fe(CN)als Fe[Fe(CN)6ls More Stable(b) Least stable

C. Equilibrium between a Solid and Its Ions in Solution Step 25a. Pb(NO₂)₂ went from clear liquid to whto solid after Noot was se added Step 25b. equation Step 26a. HNO added (ause the solution to go back to clear Step 26b. explanation. Step 26c. equation D. Equilibrium of the Tetraamminecopper(II) Complex Ion, [Cu(NH3)4]²+ Step 29a. color (open) hitrate went from light blue to dark blue when ammassa was adde Step 29b. equation Step 30. Nitric acid added to the solution with Cu(NO₂)2 and ammonia the solution went back to the light blue color