Chemistry Unit- Lesson 9

Lesson 9:
Physical or Chemical?
6 trays set up as follows:

tray 1: a bowl with an ice cube
tray 2: a tube containing vinegar and one containing baking soda.
tray 3: an apple, plate and a knife
tray 4: a tube containing vinegar and a bowl containing steel wool
tray 5: a plastic back containing a rock and a hammer

tray 6: a candle and a lighter

Their job was to determine whether a chemical change, physical change or both took place.

Phyiscal:
the ice- changes in state of matter
the rock- change in shape
the apple- change in shape

Chemical:

the apple- color change caused by oxidation
the steel wool- rust formation caused by oxidation
the baking soda and vinegar- bubbling, gas formation

the candle- gas formation, odor

We watched the candle (small, birthday cake candle) until it was completely gone. This showed even more than the previous experiment....the wax was almost completely vaporized, where as the previous one had a substantial pile of wax left once it was burned out. While it burned we talked about the parts of the flame. Where it is the hottest, coolest and what is going on in each part. We also talked about open flame safety rules.

I am also fairly certain I could give them a box of baking soda and a bottle of vinegar and they'd be entertained for a very long time.