Aqueous Equilibria

The title is video link (where available). PDF file is below the description.

  • Amphoteric Hydroxides – Add NaOH to samples of Al(NO3)3 and Fe(NO3)3 to form insoluble metal hydroxides, then add HNO3 and more NaOH to different samples of each to identify which metal hydroxides are amphoteric.
  • Buffer Capacity Demo – Contrast the buffer capacity of water, 1 M CH3COOH/NaCH3COO, and 0.1 M CH3COOH/NaCH3COO by adding increments of 6 M HCl to each in the presence of an indicator.
  • Common Ion Effect Demos
    • HCl – Add concentrated HCl (aq) to saturated NaCl (aq) to cause precipitation of NaCl (s).
    • Mg(OH)2 – Mix 1 M MgCl2 (aq) and 1 M NH3 (aq) to form Mg(OH)2 (s). Add NH4Cl (s) and NH4+ removes OH to reform NH3, so Mg(OH)2 dissolves to replace OH.
    • NaAc – Add NaCH3COO to a solution of acetic acid and indicator; the color change accompanying the change in pH shows the equilibrium shift caused by the common ion effect.
    • Common Ion Effect Demos.pdf
  • Milk of Magnesia Demo – Add HCl gradually to Milk of Magnesia in a beaker (an aqueous suspension of Mg(OH)2) to show the dissolution of Mg(OH)2 as the pH decreases.
  • Precipitates and Complexes of Silver – Add a series of 7-9 reagents to Ag(aq) in succession to produce a series of precipitates and complexes.