This demonstration makes a white precipitate by mixing equal amounts of silver nitrate and potassium chloride.
AgNO3 (aq) + KCl (aq) → KNO3 (aq) + AgCl (s)
When sodium hydroxide is dissolved in water it feels warm, which indicates an exothermic reaction.
NaOH (s) → Na+ (aq) + OH- (aq)
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
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)
Acetone dissolves a Styrofoam cup because of the principle like dissolves like.
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.
This simple activity can make DNA a real and visual thing for students.
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!
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.
When a flower is dipped in liquid nitrogen (-196°C) it is instantly frozen. Liquid nitrogen boils at room temperature. The “fog” that we see is condensed water vapor though, not nitrogen gas.