Chemistry Blog #3

The main ideas that we have been focusing on are energy and pressure. We learned that there are 2 types of energy, kinetic and potential energy.Potential energy is energy that is stored and not yet used, Kinetic energy is energy that is moving. Energy creates heat and heat is an example of kinetic energy. We did an experiment showing how food coloring moves in different water temperatures, The food coloring in the hot water moved faster and spread throughout the water faster. This is because the hot water is conducting more energy and the particles are moving faster. The food coloring in the cold water spread much slower, because there's not as much energy because the particles are moving slower. We talked about why the alcohol level in a thermometer rises or falls when the thermometer is in contact with warmer or colder objects, The answer to that is thermal expansion, if the temperature of whats being measured is hotter than the alcohol then the alcohol will rise in the thermometer. Same for when the temperature is colder than the alcohol, the alcohol will fall. Also, you can't measure your own temperature with your own hand because it'll feel the same temperature as your forehead because you have the same body temperature all over. Next, we started talking about pressure,  We can drink a liquid through a straw because of pressure. When you suck the air out of the straw, you're creating a vacuum. The liquid fills the straw because of the vacuum and because particles move from high to low pressure. So the liquid moves from the cup, or can to the straw. We read an article about scuba diving,gas and pressure related to it.The water pressure, as the divers descends, increases greatly. The gas and pressure in your body increases and the gas has to go somewhere. The gas either gets exhaled, or goes into the bloodstream. Diving can be very dangerous, you have to descend and ascend slowly so your the gas and pressure in your body can change with the water pressure. If it can't change with the surrounding air pressure, the alveoli in the lungs can rupture and air can enter the bloodstream which causes a blockage which can lead to many problems and may result in death. There were a few laws mentioned in this article. Boyle's law states: The volume of a gas sample varies inversely with its pressure. Harry's law states: The amount of gas that will dissolve in a liquid at a  given temperature varies directly with the pressure above the liquid. Next, we did a lab that was called the Pressure vs. Volume lab. We connected a syringe to a pressure sensor and connected that to LabQuest, First,we recorded the pressure when the syringe was at 10mL. That was .98 atm. Then we recorded the pressure every time we went down 2mL. At 8mL, the pressure was 1.107 atm. The pressure at 6mL was 1.54 atm, 4ml was 2.1 atm and the pressure at 2mL was 2.3 atm. The we went back up, starting at 10mL, we went up every 2 mL. At 12mL ,the pressure was .84 atm. At 14mL, the pressure was .71atm. The pressure at 16mL was 0.62 atm, 18mL was 0.56 atm and at 20mL , the pressure was 0.51 atm. From this lab, we learned that the smaller the volume, the higher the pressure, and the bigger the volume, the lower the pressure.