Behavior of Gases

Today in class we learned about the properties of gases and had a few gas demos, after going over and reviewing our tests.

The first gas demo was with iodine crystals. The crystals were heated up and turned into a pinkish/purple color of gas.. There is a myth that since you cannot see gases, they are not real, which this experiment obviously proves wrong.

The next demo was with Hexane. Hexane evaporates very easily into the air, and the gas acts as if it is a liquid. After a little shaking, we were able to pour it down a pipe into a flame, igniting the flame and the rest of the gas coming down the pipe.

The final demo was with baking powder, acetic acid, and a candle. Two beakers, one empty, and one filled with baking powder, are presented. A lit candle is held in both of the beakers, but nothing happens. But when you pour acetic acid into the baking powder and it reacts, if you put the lit candle in it will extinguish due to the carbon dioxide from the reaction causing oxygen, which the flame needs, to be pushed out. This reaction makes the gas act like water and can be poured into the empty beaker, which will extinguish a lit flame as well. The final part of the demo with the tube and the carbon dioxide did not work so well, but was meant so that gravity pulls carbon dioxide into an empty beaker where the candle can be extinguished.

Homework: Gases Chemthink and Behaviors of Gases worksheet.

Next scribe will be Zach Salty