Liquid Nitrogen Ice Cream
Liquid nitrogen is -196˚C and quickly freezes the ingredients into ice cream. The nitrogen boils out leaving deliciously creamy ice cream. The “fog” that we see is condensed water vapor though, not nitrogen gas.
- Condensation / Cryogenics / Freezing / Mixtures / Physical Change / Problem Sets / Vaporization
- 2.3c / 3.3a / 3.3c / 5.4b / 5.4e / CH.2h / CH.5d / PS.2b / PS.5a / PS.7b
Shrink A Balloon
When a balloon is placed in liquid nitrogen the air inside it is condensed from the cold (-196°C), causing the balloon to shrink. Once the balloon is removed it will regain its size as the air heats up. Liquid nitrogen boils at room temperature. The “fog” that we see is condensed water vapor though, not nitrogen gas.
- Condensation / Cryogenics / Gas Laws / Lesson Plans / Physical Change / Problem Sets / Vaporization / Videos
- 2.3c / 3.3c / 5.4b / CH.5b / CH.5d / PS.5a / PS.7b
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)
Genie in a Bottle
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
Diet and Regular Soda
Diet soda contains artificial sweeteners while regular soda has sugar in it. Artificial sweeteners are so sweet so only a small amount is needed, where as much more sugar is needed to achieve the same sweetness. Because regular soda has more mass in the same size can, it is more dense than the diet soda.
- Density / Physical Change / Problem Sets / Uses Household Items
- 3.3c / CH.2h / ES.10a / K.5c / PS.2d / PS.5a
Colored Flames
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.
- Chemical Change / Color Change / Combustion / Energy Transformations / Excited States / Lesson Plans / Light / Problem Sets / Sound / Thermal Conduction / Wavelengths of Light
- 5.3b / 6.2e / CH.2i / CH.3e / ES.11c / ES.12d / PH.7a / PH.9a / PH.9c / PS.5b / PS.6b / PS.7c / PS.9d
Collapse a Soda Can
When a small amount of water is heated inside the can, steam is produced, filling the can. When the can is inverted into cold water, all of the steam condenses quickly causing the can to implode.
Aluminium Foil and NaOH
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