Demonstrating Chemical Concepts Sarah Gray Lisa Ashenhurst Nelson

Demonstrating Chemical Concepts Sarah Gray Lisa Ashenhurst Nelson High School HDSB

Why? Some demos can be used for multiple concepts n Spiral staircase curriculum results in recurring concepts n Variation helps reduce ‘spoilers’ n Sharing ideas and applications n

Types of Reactions Grade 10 and 11

Decomposition Reaction Traditional Alternative Elephant’s Toothpaste § Yeast as the catalyst (Mn. O 2 as a catalyst) § In a pop bottle Benefits: • Greater visual impact • Can relate to biological processes

Double Displacement Reaction Traditional Alternative Potassium iodide + Lead nitrate Tangerine Surprise § Production of a gas § Use of an indicator Benefits: • Could be third time the students have seen the traditional demo • Visually surprising.

Single Displacement Reaction Traditional Copper metal + Silver nitrate Benefits: Alternative Mossy Zinc + Hydrochloric Acid § Capture the gas in a balloon § Light the balloon! http: //www. youtube. com/watch? v=kkn. U 6 cp. K WL 0 • Students enjoy fire. • Leads to the Activation Series

Combustion Reaction Traditional Alternative http: //www. graspr. com/videos/acetylene-balloon-1 Light a candle (dramatic or otherwise) Benefits: Calcium carbide + water § Capture the acetylene produced § Light! • Student’s enjoy fire, again! • Example of incomplete combustion. • Combination of reactions.

Acids and Bases Grade 10

p. H Scale Traditional Alternative Wine/Water/Beer Rainbow Burrette § Universal Indicator at each p. H at the same time Benefits: • Use of an indicator • Visual representation of the gradual changes

Gas Laws Grade 11

Boyle’s Law Traditional Alternative Egg in a jar Cartesian Diver Marshmallow in a syringe § Manipulate the volume of the marshmallow by moving the plunger Benefits: • Hand’s on • Challenge the student’s first

Combined Gas Law Traditional Alternative Pop Can Implosion Dime Challenge § Benefits: • Hand’s on § Provide students with a dime in shallow water, a jar, and a candle. Pick up the dime without touching the water • Challenge the student’s first

Intermolecular Forces Grade 11 and 12

Hydrogen Bonding Traditional Alternative Bend Water with a Balloon Defy Gravity Benefits: § • Discrepant event § Mason jar with window screening Fill with water and turn upside down • Opportunities for experimentation

Electrochemistry Grade 12

Oxidation States Traditional Alternative Progression of Mn 7+, Pop Can Challenge Mn 6+, Mn 4+, Mn 2+ § Use Cu. SO to 4 using p. H promote corrosion Benefits: • Student participation • Application Based