Main Group Elements

 

Acidic and Basic Oxides – Dissolve several oxides (CaO, ZnO, CO2, P4O10) in water containing universal indicator to show a range of basic and acidic oxides.

Aluminum and NaOH – Add aluminum foil to NaOH (aq) to produce Al(OH)3 (aq) and H2 (g). Use a lighted splint to ignite the hydrogen gas produced.

Black Carbon Snake – Show the dehydrating properties of concentrated H2SO4 by adding it to sugar in a tall beaker to produce a black “snake” of carbon that grows out the top of the beaker.

Combustion of Magnesium in Dry Ice – Demonstrate the combustion of magnesium in dry ice, resulting in a luminous effect as well as the production of MgO and elemental carbon.

Combustion of Sulfur in Oxygen – Burn sulfur in air enriched with O2 to produce SO(g), then dissolve the product in water containing universal indicator to show that SO2 is an acidic oxide – this shows how acid rain results from burning high sulfur coal.

Effect of Temperature on the NO2 <-> N2O4 Equilibrium – Immerse sealed tubes of NO2/N2O4 in hot and cold water to show how temperature shifts the equilibrium position and to show the reversibility of the shift; red-brown NO2 predominates at high temperatures and colorless N2O4 at lower temperatures.

Gas Discharge Tubes of the Noble Gases – show that different gases give different colors when subjected to an electric discharge (H2 tube also available)

Genie in a Bottle – Use MnO2 to catalyze the decomposition of 30% H2O2, producing a large cloud of hot water vapor. The heat generated is intense enough to shrink the 2 L bottle used for the demo.

Electrolysis of Water – Electrolyze water (dilute Na2SO4 solution with indicator) in the Hoffman apparatus to decompose it into its component elements, hydrogen and oxygen. If desired, you can test the H2 (g) and/or O2 (g) produced with a flame and a glowing splint, respectively.

H2/O2 balloons– Ignite a balloon filled with a stoichiometric mixture of hydrogen and oxygen to show the extremely exothermic reaction to produce water. Different ratios can be used to discuss limiting reactants.

Lake Nyos Demo – Pour CO2 (g) down an enclosed set of steps to extinguish candles on each step, demonstrating the fluidity of gases, and recreating (on a small scale) a tragic natural disaster.

Penny vs Nitric Acid – Read Ira Remson’s own account of his first encounter with chemistry as you repeat his experiment by pouring concentrated nitric acid over a copper penny.

Periodic Properties – Add pieces of Li, Na, K, Mg, and Ca, to beakers of water with phenolphthalein to observe the reactivity of metals from different parts of the periodic table.

Potassium and Water – Drop a piece of potassium into a few inches of water and phenolphthalein in an aquarium to produce H2 (g) and KOH (aq) – the heat of reaction ignites the H2 (g) and a lavender flame is observed, and the indicator turns pink from the formation of KOH.

Production and Combustion of Carbon Monoxide – Add concentrated sulfuric acid to formic acid to produce H2O and CO (g), then ignite the CO (g) to show that it burns with a blue flame.

Slime! – Make a cross-linked gel by mixing solutions of polyvinyl alcohol and borax; use this demo to relate concepts such as polymers and hydrogen-bonding to a commercial product students are familiar with.

Smashing things with Liquid Nitrogen – Demonstrate the coolant properties of liquid nitrogen by freezing a racquet ball or another object of your choice and smashing it.

Sound: Phosphorous and Potassium Chlorate – Tap a very small pile of red phosphorus and KClO3 with a hammer to show a reaction that produces light, sound, and heat, and recreates on a larger scale the reaction that occurs when you strike a match.

Zinc and HCl – Immerse mossy zinc in HCl (aq) to produce ZnCl2 (aq) and H2 (g). Use a lighted splint to ignite the hydrogen gas produced.

ZnO and HCl – Add ZnO to water to show that it does not dissolve appreciably, then add acid to show that a basic oxide reacts with (and therefore dissolves in) an acid