Summary Chemistry Module 5 — Energy Changes

EXOTHERMIC :
eg ENDOTHERMIC :

eg
combustion sports injury packs
·
·




A A
·
oxidation ·
thermal decomposition
N
M
neutralisation
self-heating cans
·
·




activation
energy
-




-




↳ the minimum amount
of P
> >
R
energyneeded
to stat
is
y
*
-




activation
energy
REACTANTS' > PRODUCTS

· energy energy
· BOND ENER
bond
en
P R ~
-




- - - - -




Bond
> > ene
PROGRESS Of reaction (time) PROGRESS Of reaction (time) REACTA
TEMP CHANGE
.
(AO) :

·
In ELECTROCHEMICAL CELLS :
REACTANTS' PRODUCTS'
↳ two electrodes
·
EXOTHERMIC <temp increase
.
<
decrease energy energy
↳
·

ENDOTHERMIC >temp .




an
electrolyte



ENERGY CHANGES
different metals (og varying reactivity

illl11 IK
two
·




placed in electrolyte to produce electricity
.

solution that can conduct
electrolyte -
> a
electricity
·




-




. a solution of an ionic compound (
leg HYDROGEN FUEL CELLS :

current
-
~
V (flowge)
cells can only produce electricity for certain period of time
·

a e e




-
e-
↳ chemicals will run out reaction stops




I
H-
e
2

(fuel) Coxidising
(413x
Me agent(
V 1 5V V .0 V
1 V 0 OV + (49
202
.
+
2e
.




~ ~ ~ Hz > CH +
Ht 02 + 4 >



&
1 N >
N >



OR H+
O2
>
is reduced


2H2 < 4H
+
+ 4e (gains et