Class notes 2/24-27/17
Energy in a Chemical reaction:
reactants
yields
2H2 +O2
products
2H2O
All chemical reactions require energy to start this is called the
activation energy (the difference between the energy in the
reactants and the top of the hump where the reaction proceeds on its
own).
Exothermic reaction - a reaction that releases energy, product
energy lower that reactant energy. The reaction feels hot. (exo
means out)
E
n
e
r
g
y
Time
Thermal energy or
Heat
Endothermic reaction – a reaction that absorbs energy, the product
energy is higher than the reactant energy. (endo means in)
en
er
gy
Time
Thermal Energy
or Heat