energy changes and analysis tests

?
  • Created by: linda
  • Created on: 21-05-11 18:14

Energy changes.

energy is measured in joules (J). values for heat energy and dietry information are soemtimes given in calories... 1 calorie=4.2j

a calirometre can be used to measure the amount of heat produced when a substance is burnt. to find the overall energy change for a reaction you subtract the energy for the product from the energy or reactants..

negative value= exothermic
postive value= endothermic

endothermic= >takes in heat
                      > surroundings cool down
                      > more energy is taken in to break the bonds
                      >step up on energy level diagram

exothermic = > gives out heat energy
                     >more energy is released
                    …

Comments

No comments have yet been made