Energy and Chemical Reactions

What makes this hot air balloon rise?  Actually, a propane burner heats the air inside the balllon until the air is heated enough to be less dense than the air outside, causing it to rise.  Energy in the form of heat is needed to make this work.  Similarly, energy (usually in the form of heat) is needed in many chemical reactions.

For Students:
The science of heat and work is called thermodynamics.  This week we will be learning about the relationships between energy changes, heat and work.  We will also be talking about how we can determine whether a chemical reaction is product favored or reactant favored.  Energy can be defined as kinetic or potential.  Kinetic energy is the energy of motion, it can describe the motion of atoms, molecules, a moving tennis ball, or automobile.  Basically anything moving in anyway has kinetic energy.  Potential energy is stored energy and is directly related to an object's position.  Holding a ball at the top of a waterfall has potential energy and so does energy stored in fuels.  Finally, the Law of Conservation of energy states that energy can neither be created or destroyed.  Energy is always constant, it can remain the same or change forms, but the amount of energy in the universe is always constant.
The answers to last week's quiz are:
1.  OH-    -->  hydroxide
2.  Cyanide  -->  CN-
3.  Carbonate  -->  CO3 (-2)
4.  nitrite  --> NO2 (-)
5.  PO4 (-3) --> phosphate
6.  NO3 (-) --> nitrate
7.  SO3 (-2) --> sulfite
8.  CLO (-) --> hypochlorite
9.  sulfate --> SO4 (-2)
10.  chlorite --> CLO2 (-)
11.  chlorate --> CLO3 (-)
12.  perchlorate --> CLO4 (-)
13.  CrO4 (-2) --> chromate
14.  CH3CO2 (-) --> acetate
14.  MnO4 (-) --> permanganate
15.  HCO3 (-) --> bicarbonate

Hope everyone did well!

For Parents:
The quiz grades seem to be slipping a bit, so just a reminder: if your child needs help please instruct them to see me after school or during lunch break.  I am always willing to help!  Also, FYI  we will be going on a field trip to the Great Lakes Science Center in Cleveland.  This trip is still a few weeks away and permission slips will be going home soon.  Thanks again for all you do!