Today we started class by doing the Combustion Lab as a class. This lab's main question was: How much energy is released in the burning of candle wax? To figure this out, we measured and massed 100 ml of water in a beaker and then placed it over a small, burning candle underneath. Before we placed it above the burning candle, we massed the burning candle. We waited for the candle to heat up the beaker a little bit before taking the water's temperature again and then massing the candle one more time. Once we concurred that the mass went down because some of the wax had changed because of the reaction that took place (Wax + O2 -> CO2 + H2O + Heat), we were then able to plug our data into our formula (Heat = mc [delta] T).
Scroll up for the two pictures that explain all of our data and what we ended up doing for the equation.
After we finished the Combustion Lab, Mr. Tucker checked in our homework. We went through a few problems and if you want to see some problems and the answers, Kim posted some on her blog for Tuesday, March 22.
We learned something new today : Energy Diagrams! Mr. Tucker pointed out like 10 times that an Energy Diagram ( which has a curve) is NOT the same thing as a Heating Curve ( which looks more slanted steps ( 2 plateaus, 3 slopes). So don't confuse them! Here are the notes/diagrams from these two pages ( pages 7 & 8). ( scroll up for pictures)
Our homework for today is to do the Unit 10 Chemistry Practice packet ( but skip the math skills and reading for information sections) and if you want to, the 3rd quarter food review. It's due tomorrow ( Thursday) and I'm putting a picture on to show you what's required in the flyer. ( scroll up for pictures)