Sub-category Demo Name Brief Description Demo Notes Demo # Type of Item
Colligative Properties of Solutions  Osmotic pressure of a sugar solution Regular:  put dark or colored corn syrup in thistle tube and put a soaked membrane over the end using twist ties.  Hook it onto a ring stand and into a beaker of water to observe the solution going up in the tube with time.  (See variations in details.)   Also on Shakhashiri tape III #42.  Small scale:  uses a copper sulfate solution where you add crystals of sodium hexacyanoferrate(II) and a brown semipermeable membrane is formed, water enters the membrane, it swells, bursts, throws out the concentrated sodium hexacyanoferrate(II) solution, which reacts with copper in solution to make more copper hexacyanoferrate(II), making solid brown streamers and membranes.  It is done on the overhead and looks like growing sea grass.  I tried it out and it grew 1/2 inch in 5 minutes.  I couldn't really see the membranes bursting and they are small balls, but it looked kind of neat anyway. 76 Demonstration
Colligative Properties of Solutions  Colligative Properties - melting points watch glasses on an overhead or beakers contain ice or ice that had salt poured on it to show the different melting rates   100 Demonstration
Colligative Properties of Solutions  sugar, diet coke A coke can is opened and heated to evaporate the water leaving the sugary residue.   150 Demonstration
Colligative Properties of Solutions  Osmotic pressure of a sugar solution   Shakhashiri tape III #42. M58 Movie
Colloids Formation of a colloid Sterno-alcohol gel; thixotropy, dilatancy.  Liquids are mixed to give a gel which can be lighted   38 Demonstration
Colloids Tyndal effect-chemical sunset on overhead projector Na thiosulfate and HCl; disproportionation.  Can be tricky.  A cardboard sheet containing a small hole is placed on the overhead projector.  A solution is added to beaker containing a different solution which changes the color of the light projected to resemble a sun set.   65 Demonstration
Colloids Cuprammonium rayon     118 Demonstration
Dissolution Processes Solubility, polar and nonpolar solvents water, toluene, NaCl, naphthalene; Solubility of solids in liquids, temperature.  Add the two solids to 4 beakers of the solvents to see what dissolves in what.  Do not add too much solid or all won't dissolve.  Solubility of a limestone rock in 1M HCl, salt in water.   109 Demonstration
Electrolytes and Non-Electrolytes Electrical conductivity of liquids Light bulb with H2O, acetic acid, K2CrO4.  A beaker is covered with a Petri plate lid containing the 2 copper electrodes.  The electrodes are immersed into assorted solutions to test whether they light a bulb, and how brightly.   56 Demonstration
Rates of Dissolution and Saturation Supersaturation-sodium acetate crystallization A supersaturated solution of sodium acetate is in a long glass tube.  A single solid crystal causes the solution to solidify.  OR pour the solution onto a surface containing a crystal and the solution forms a stalagmite.   Also see 163 for other crystals, and 146 for other exothermic reactions.  Also on Shakhashiri tape III #41; Close up on Chemistry Ealy 1:19 (1:21 min) 106 Demonstration
Rates of Dissolution and Saturation Crystal formations Saturated solutions form crystals, several variations including waterglass.   Chemical garden, microcrystals, sugar and salt, other crystal formations 163 Demonstration
Rates of Dissolution and Saturation Supersaturation-sodium acetate crystallization A supersaturated solution of sodium acetate is in a long glass tube.  A single solid crystal causes the solution to solidify.  OR pour the solution onto a surface containing a crystal and the solution forms a stalagmite.   Shakhashiri tape III #41; Close up on Chemistry Ealy 1:19 (1:21 min)  (For Ealy set timer to zero when first text rolls on screen.) M36 Movie
Solubility rules Disappearing ink, invisible writing, Goldenrod messages  EtOH, thymolphthalein, NaOH;  The wet ink looks dark blue but it quickly becomes colorless on paper.  Various invisible inks are made for signs, etc.  Some brands of Goldenrod colored copy paper turn red when sprayed with household ammonia (write first with white wax or invisible tape)   53 Demonstration
  Solubility of a gas: Ammonia fountain dissolves in water, water fills up inverted flask  Tricky to set up, but it works--unknown if students liked it much.  Also on Shakhashiri tape 1 #3,4,6; Close up on Chemistry Ealy 16:04 (2 min) 33 Demonstration
  Solubility of a gas: Ammonia fountain dissolves in water, water fills up inverted flask  Shakhashiri tape 1 #3,4,6 M10 Movie
  Solubility of a gas: Ammonia fountain dissolves in water, water fills up inverted flask  Close up on Chemistry Ealy 16:04 (2 min)  (Set timer to zero when first text rolls on screen.) M11 Movie
Electrolytes and Non-Electrolytes Plastic Easter eggs as models for dissociation     107 Demonstration
Electrolytes and Non-Electrolytes glowing electric pickle-UT, the eyes of Texas are upon you UT is spelled out on a plastic grid using specially wired pickles.  The wires are plugged in causing the pickles to glow yellow orange.  A smaller version uses a single pickle stuck on nails of a board.   The small version can be available routinely, but the larger version takes a longer prep time-at least 1 hour.  Can have class sing the eyes of Texas while UT pickle glowing.   135 Demonstration
Solubility rules Limiting reactant concept (PbCrO4) Potassium chromate and lead nitrate give a thick yellow precipitate.  One reactant is diluted  to show the ppt decreases.   Also illustrated by Dr. Laude using 6 bolts, 4 nuts, 12 washers on an overhead projector  (See demo #152) 2 Demonstration
Solubility rules Precipitation reactions various 2 clear solutions are mixed to give different colored precipitates.  K2CrO4 + Pb(NO3)2 for yellow, (NH4)2CO3 + CaCl2 for white.  The barium hydroxide/sulfuric acid ppt can be used with phenolphthalene to show an acid/base ppt. Very popular-The potassium chromate, lead nitrate reaction gives a thick yellow ppt.    (Also see #2 for limiting reactant using ppt) 71 Demonstration
Solubility rules Equilibrium by diffusion of coloring in water add drops of coloring to a big beaker of water, let it sit and become uniform, notice the mixing of the color throughout class   93 Demonstration
Solubility rules Supersaturation-sodium acetate crystallization A supersaturated solution of sodium acetate is in a long glass tube.  A single solid crystal causes the solution to solidify.  OR pour the solution onto a surface containing a crystal and the solution forms a stalagmite.   Also see 163 for other crystals, and 146 for other exothermic reactions.  Also on Shakhashiri tape III #41; Close up on Chemistry Ealy 1:19 (1:21 min) 106 Demonstration
Solubility rules Solubility, polar and nonpolar solvents water, toluene, NaCl, naphthalene; Solubility of solids in liquids, temperature.  Add the two solids to 4 beakers of the solvents to see what dissolves in what.  Do not add too much solid or all won't dissolve.  Solubility of a limestone rock in 1M HCl, salt in water.   109 Demonstration
Solubility rules Crystal formations Saturated solutions form crystals, several variations including waterglass.   Chemical garden, microcrystals, sugar and salt, other crystal formations 163 Demonstration
Solubility rules Supersaturation-sodium acetate crystallization A supersaturated solution of sodium acetate is in a long glass tube.  A single solid crystal causes the solution to solidify.  OR pour the solution onto a surface containing a crystal and the solution forms a stalagmite.   Shakhashiri tape III #41; Close up on Chemistry Ealy 1:19 (1:21 min)  (For Ealy set timer to zero when first text rolls on screen.) M36 Movie