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)

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)

Sodium Hydroxide in Water

sodium hydroxide ions in solution

When sodium hydroxide is dissolved in water it feels warm, which indicates an exothermic reaction.
NaOH (s) → Na+ (aq) + OH- (aq)

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

Water Flowing Uphill

A candle is placed in a crystallizing dish containing water and lit. A beaker is placed upside-down over the candle. The candle will eventually go out and the water level in the beaker will rise.
CxHy­ (wax) + (x +y/4)O2 (g) → x CO2 (g) + (y/2)H2O (l)

Super Saturated Sodium Acetate

A super saturated sodium acetate solution is poured onto a sodium acetate seed crystal. The seed crystal provides a crystalline structure template for the sodium acetate ions to form on. This is an exothermic process.

Colorful Oxidation States

This demo has a solution in a flask that changes color from pink to blue to green to yellow to orange as the solution is stirred. The different colors are due to the different oxidation states of Mn.

Non-Burning Dollar Bill

non burning dollar bill ethanol and water

When the bill is dipped in the water/alcohol mixture then lit on fire, the water protects the bill from burning. A large amount of the alcohol is vaporized from the heat causing a large flame around the bill.
C2H5OH + 3O2 → 2CO2 + 3H2O

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)

Jumping Flame

This demo uses a stove made out of aluminum cans that can be lit using knowledge of vapor pressure. When the acetone surrounding the stove is lit, the acetone in the stove boils, releasing vapors that are then lit on fire.
CH3OCH3 + 3O2 → 2CO2 + 3H2O

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.

Gold and Silver Pennies

plating pennies with zinc silver pennies gold pennies

This demo uses sodium hydroxide to plate Zn on the surface of a copper penny, making it appear silver in color. Zinc is oxidized in sodium hydroxide. The remaining electroplating process is not fully understood. The silvery penny can be heated to melt the zinc and copper together, creating a gold colored alloy.

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)

Colored Flames

manganese strontium sodium copper potassium salts burning in ethanol

When different ionic compounds are heated, electrons around the metal atom become excited and jump energy levels. When the electrons fall back to ground state they release light and heat energy. The amount of energy released determined the wavelength and color of the light released, resulting in different colored flames.

Blue Bottle Demo

methylene blue equilibrium under basic conditions

Under basic conditions glucose is oxidized while methylene blue is reduced, changing from blue to colorless. The reduction reaction can be reversed by shaking the flask which forces oxygen into solution, which oxidizes the methylene blue, thus turning it back to blue. If the flask is let sit, the oxygen will come out of solution making the solution colorless and ready to shake again.

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

Ammonium Nitrate in Water

ammonium nitrate ions in solution

When ammonium nitrate is dissolved in water it feels cold, which indicates an endothermic reaction.
NH4NO3 (s) → NH4+ (aq) + NO3- (aq)

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