chemistry - rates of reaction & energy changes: heat energy changes in chemical reactions (7.9 - 7.16)

7.9 what changes do changes in heat energy accompany?

salts dissolving in water

neutralisation reactions

displacement reactions

precipitation reactions

7.9 how to show heat changes

measure temp. changes when reactions (prev. flashcard) take place in solution

7.10 exothermic change/reaction

heat energy given out

(energy transferred from stores of energy in chemical bonds → surroundings)

7.10 endothermic change/reaction

heat energy taken in

(energy transferred from surroundings → stores of energy in chemical bonds)

7.12 breaking bonds - endothermic/exothermic?

endothermic

7.12 making bonds - endothermic/exothermic?

exothermic

7.13 overall heat energy change for reaction is exothermic if:

more heat energy given out in making bonds in products than taken in in breaking bonds in reactants

7.13 overall heat energy change for reaction is endothermic if:

less heat energy given out in making bonds in products than taken in in breaking bonds in reactants

bond energy units

kJ mol^-1

7.14 calculate energy change in reaction given energies of bonds

7.15 activation energy meaning

minimum amount of energy needed by colliding particles for reaction to occur

7.16 identify activation energy on reaction profile

from reactants line → highest point on curve

7.16 reaction profile - endothermic reaction

7.16 reaction profile - exothermic reaction