Electrolysis

Electrodes made from pencil lead are attached to a 9V battery to electrolyze various solutions. Oxidation occurs and the anode and reduction occurs at the cathode. When a solution of tin (II) chloride is electrolyzed tin metal and chlorine gas are produced:
SnCl2 (aq) → Sn (s) + Cl2 (g)
When a solution of copper (II) chloride is electrolyzed copper metal and chlorine gas are produced:
CuCl2 aq) → Cu (s) + Cl2 (g)

Rates of Yellow

A reaction between two white solids occurs when lead nitrate and potassium iodide are shaken forcefully producing a mixture of yellow and white solid products. The reaction occurs almost instantaneously when aqueous solutions of these compounds are mixed, precipitating yellow lead iodide.

Pb(NO3)2 + 2KI → PbI2 + 2KNO3

Bubbling Magnesium

When magnesium ribbon is placed in hydrochloric acid, hydrogen gas is produced causing the mixture to bubble.
Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g)

If they hydrogen gas is collected, it can be ignited to demonstrate the potential safety concerns of an evolved gas.
H2 (g) + O2 (g) → H2O (g)

Thermite

thermite, cannon balls

As two rusty cannon balls (one covered in aluminum foil) are smashed together, sparks and a cracking sound are produced.
Fe2O3 (s) + 2Al (s) → Al2O3 (s) + 2Fe (s)

Igniting Magnesium

burning magnesium

When magnesium is ignited, it is readily oxidized by oxygen in the air producing an incredibly bright light and intense heat.
2Mg (s) + O2 (g) → 2MgO (s)

Mass the Gas

In this demo, baking soda and vinegar are mixed in a plastic storage bag. The reaction container is massed before and after the reaction for students to see the Law of Conservation of Mass in action.
NaHCO3 (s) + CH3COOH (aq) →CO2 (g) + H2O (l) + CH3COONa (aq)

Hydrogen Balloons

hydrogen balloon explosion

This demo shows the explosiveness of hydrogen, by igniting a balloon filled with hydrogen.
2H2 (g) + O2 → 2H2O (g)

Colorless to White

silver nitrate with potassium chloride

This demonstration makes a white precipitate by mixing equal amounts of silver nitrate and potassium chloride.
AgNO3 (aq) + KCl (aq) → KNO3 (aq) + AgCl (s)

Zinc + Ammonium Nitrate

This is a very exciting exothermic reaction that produces a flame and a lot of smoke.
Zn + NH4NO3 → N2 + ZnO + 2 H2O, NaCl is a catalyst

Red Sunset

The reaction of sodium thiosulfate and hydrochloric acid produces colloidal sulfur which clouds the solution. As the sulfur concentration increases, shorter wavelengths are scattered and longer ones pass through, this causes an increase of reddish color to appear on the overhead.
Na2S2O3 + HCl → 2NaCl + SO2 + S + H2O

Making Chalk

This demo shows how a precipitation reaction works. The precipitate formed is a common ingredient in chalk.
CaCl2 (aq) + Na2CO3 (aq) → NaCl (aq) + CaCO3 (s)

Lemon Fizz

lemon reaction with baking soda

When basic baking soda (NaHCO3) is combined with acidic lemon juice (mainly citric acid, H3C6H5O7) an acid base reaction occurs. The reaction releases CO2 which can be captured using dish soap to form bubbles.
H3C6H5O7 (aq) + 3 NaHCO3 (s) → 3 CO2 (g) + 3 H2O (l) + Na3C6H5O7 (aq)

Gummy Bear Sacrifice

gummy bear in potassium perchlorate

Potassium chlorate is such a strong oxidizer that when a gummy bear, which is mostly sugar, is placed into it, the sugar is oxidized violently producing noise and a flame. This demo can be used to discuss strong oxidizers as well as how much energy is in sugar.

Genie in a Bottle

decomposition of hydrogen peroxide

This demo makes use of the catalytic decomposition of hydrogen peroxide to produce a column of steam out of a flask, that looks like a genie coming out of a bottle.
2H2O2 → 2H2O + O2, KI is a catalyst

Elephant’s Toothpaste

decomposition of hydrogen peroxide elephant's toothpaste old foamy

Hydrogen peroxide is decomposed quickly in liquid soap with the help of a catalyst to create a large volume of foam that grows out of a graduated cylinder. The soap bubbles contain oxygen.
2H2O2 → 2H2O + O2, KI is a catalyst

Decomposition of Ammonium Dichromate

ammonium dichromate on fire, decomposition

This demo decomposes ammonium dichromate using a fuse soaked in ethanol. The reaction is a violent one, that resembles a volcano. Ammonium dichromate is an orange solid, while chromium (III) oxide is a dark green solid.
(NH4)2Cr2O7(s) → Cr2O3(s) + N2(g) + 4H2O(g)

Chemistry Pop Guns

This demo harnesses the reaction of baking soda and vinegar to blow a cork off a test tube.
NaHCO3 (s) + CH3COOH (aq) →CO2 (g) + H2O (l) + CH3COONa (aq)

Black Foam

When sugar is reacted with concentrated sulfuric acid it creates a black foam made of elemental carbon. The water that is produced in the reaction is gaseous and causes the foam to rise.
H2SO4 + C12H22O11 → 12C + 11H2O + a mixture of acid and water

Aluminium Foil and NaOH

aluminum foil and sodium hydroxide produce hydrogen gas

This demo simulates what happens when Drano is poured down a clogged drain; the hydrogen gas produced forces gunk out of the drain. Also, this demonstration is a good safety example of why bases need to be handled carefully – they can be corrosive, especially to metals. If the hydrogen gas is collected and ignited, this demo shows the safety hazards that evolved gases can have.
2Al + 2NaOH + 6H2O → 2NaAl(OH)4 + 3H2