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)

Fake Blood

This demonstration makes iron (III) thiocyanate complexes that are deep red in color, resembling fake blood.

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

Silly Putty

polyvinylacatate, silly putty polymer

This is a hands on activity that demonstrates how chemical reactions change the properties of a substance. In this case, borax (sodium borate) changes the sticky properties of Elmer’s glue, to make a fun to play with putty. Elmer’s glue is polyvinyl acetate, and when sodium borate is added to it, a cross-linked polymer is created giving the glue very different properties that make for a fun activity for students!

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

Red Cabbage Indicator

red cabbage indicator in common household solutions

Anthocyanin, which is found in red cabbage, is a natural indicator that can be easily extracted.

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)

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)

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

Electrocute a Pickle

pickle electrocution

When electricity is passed through a pickle, it is conducted through Na+ and the Cl- ions that are present in the pickle. The electricity excites the electrons to a higher energy state, and when the fall back to ground state they emit a yellow/orange light.

Dry Ice in Universal Indicator

dry ice universal indicator acid base reaction

Universal indicator goes from red (pH 4) to violet (pH10) as the pH of a substance changes. Adding NaOH to water starts the solution off at pH 8-9 (blue). When dry ice is added to water it forms carbonic acid, and lowers the pH, which is the reason for the color changes. The “fog” that we see is condensed water vapor though, not carbon dioxide gas.

Disappearing Ink

This demo uses acid base chemistry and an indicator to make an ink that will appear or disappear depending on the solution added to it. Phenolphthalein, which is clear, reacts with a base, and then turns pink.

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.

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)

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

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