Chemical Reaction Lab

Bioluminescent Demo  At the start:  Luminol solution: clear blue liquid  Hydrogen peroxide: clear liquid  What we saw:  Glowing blue color and then an ugly brown color  Bubbles  Temperature rose about 7-8 ºC  Signs of a chemical reaction : Energy change (light), temperature change, gas formation, color change

Burn, Baby Burn  Signs we see:  Color change-wood went from beige to black  Odor change- smell the burning wood  Gas formation (CO 2, CO, etc…)  Heat exchange-light, heat  Mass went from ~1 gram to ~0 grams  How can this be?  Did we lose mass?

Curses Foiled Again  At the start  Solution 1 was a blue liquid (Copper chloride CuCl 2 )  Aluminum foil was a silver solid (Al)  At the end  The solution was now clear (Aluminum Chloride AlCl 3 )  There was a red/brown solid precipitate (copper Cu )  What happened:  2Al + 3CuCl 2  2AlCl 3 + 3Cu  Copper and chlorines bond breaks  Aluminum and chlorine bond  Copper falls out of solution (precipitate)  Signs we saw to indicate a chemical reaction: color change, precipitate formation, gas formation, temperature

Pittsburgh Sheep  At the beginning  Solution 2 was clear (Vinegar)  Steel wool was grayish/blackish/silver (has iron in it)  At the end  Solution 2 was clear  Steel wool has brownish/reddish spots on it- THIS IS RUST, NOT A PRECIPITATE!!  What happened:  3Fe + O 2 -> Fe 2 O 3  When iron from the steel and oxygen from the vinegar meet they bond together to give you rust  Signs we saw to indicate a chemical reaction: color change, maybe temperature

The Gas We Pass  At the beginning:  Powder 1- Sodium Bicarbonate (NaHCO 3 )  Solution 2- Vinegar (with acetic acid)(CH 3 COOH)  At the end:  Carbon dioxide (CO 2 )  Water (H 2 O)  Sodium Acetate(NaCH 3 COO)  What happened:  NaHCO 3 + CH 3 COOH  CO 2 + H 2 O + NaCH 3 COO  Signs we saw to indicate a chemical reaction: Gas formation, energy change

Cabbage Water  At the beginning:  Solution 2- Vinegar (with acetic acid)(CH 3 COOH) was clear  Solution 3- Ammonia was clear  Solution 4-Cabbage water (pH indicator) was purple  At the end:  Test Tube A: Solution 2 + Solution 4= a pink colored liquid  Test Tube B: Solution 3 + Solution 4= a green colored liquid  What happened:  Vinegar w/acetic acid is more acidic (has more H+ ions) and therefore turns pink  Ammonia is more basic (has less H+ ions) and therefore turns green  Signs we saw to indicate a chemical reaction: color change

Elephant Toothpaste  Before:  Hydrogen Peroxide – Clear liquid  Potassium iodide solution – cold, cloudy liquid  What happened:  Created potassium and iodide ions in water and oxygen gas  KI + 2 H 2 O 2  2H O 2 +K + I  Signs of a Chemical Reaction  Gas formation  Temperature change  Odor change  Color change