Accel. Chem. Blog Two

The first demo we did for this section was the one with the stink spray, which actually smelled quite nice. It showed diffusion through the air, as the particles of the spray, which started out at the front of the room, were spread around by the other air particles until they had evenly spread throughout the room. Similarly, we next did the demo with the hot and cold water. For this, drops of food coloring were put into hot and cold water and left to mix around. The food coloring in the hot water mixed much more evenly, and had distributed throughout the whole container after a few minutes. In the cold water, the food coloring mixed a little, but not much. The disparity in results was caused by the fact that the hot water has more energy in its particles, meaning they will bounce around more and move the food coloring particles around faster than in the cold water, because the cold water has less energy.

Later, we did a computer simulation that demonstrated how gas particles move. It showed that gas particles transfer energy when they bounce off each other. The transfer of energy is demonstrated by one particle gaining speed and the other losing speed. It also showed that particles of different sizes will move at different speeds, because it takes the larger particles longer to heat up and get that energy from heat. After this, we did a solid, liquid, and gas demo where we learned about the different qualities of the three states of matter and recorded them in our notebooks. For example, we were taught that solids have their particles in a lattice and are vibrating, liquid particles are free to move past and along each other, and air particles move randomly in all directions. The second part of this was the Eureka videos, which acted as a sort of review. They gave us the phrase "dance of the little lumps" to describe molecular motion, which is hilarious.

The last two experiments we did involved blowing people up and straws. For the first one, we demonstrated the power of air pressure by inflating a garbage bag while someone was sitting on it.

 Before

After

The bag was able to support Kate's weight because of air pressure. When all of us were blowing in though our straws, the amount of air in the bag increased, and eventually all of the particles bouncing off the walls of the bag was enough force to actually lift Kate off the ground. The straw experiment started by all of us getting Koolaid pouches to drink and then having to explain why the liquid rises up the straw. It's not because of suction, as I previously thought, but instead because you create a vacuum. When drinking from a straw, you suck out all the air, creating a pressure difference in the straw and in your  mouth, which in turn causes the liquid to rise up the straw and get to your mouth.