Summary Energy change & rate of reactions notes IEB

Energy-Change _
and _
Rate of Reactions -



Energy Change :




When takes place there
·



chemical
a reaction is
energy change
to
Change due :




↳
Bonds
breaking -



energy absorbed lendothermic



forming
↳
Bonds releasedexothermic
energy
-




Stronger bond recquires more
energy
to break = releases more
energy when formed




-Heatof Reaction -




Net of chemical potential of the
change energy system



Enthalpy H
·

=




·



Total amount of chemical potential of products and reactants
energy
+




Change in
enthalpy = heat of reaction (H)

I

kj
-




. mo



.......

I
--------------
&H
I
=

Energy of products Energy of reactants
I I

Or I
I

I !
↳ H Energy -
absorbedEnergy released -

, Endothermic Reactions - -
18H > 0




Reactions which transform thermal energy into chemical potential
energy



Absorb heat
·




Bonds need heat
energy
to break !!

Temperature
·

of reaction mixture will decrease



-Molecules will
gain energy
Environment around molecules will decrease temperature Kolder)

broken !!
Bonds
<Energy
·

of of
are *
Energy products reactants

---
Release than they form
·


less
energy




-Excothermic_Reactions- 1H (0)




Reactions which transform chemical potential into thermal
energy energy



Release heat
·




substances lose bonds
energy
when
forming
Temperature
·



of reaction mixture will increase


Molecules
-




will lose
energy
Environment around molecules will increase temperature (hotter
·

Bonds are formed

Releases when formed
Energy of products >
Energy of reactants
·




energy
Releases
·



to enter stable state
energy
more




-




-
--------toda :
1
Energy
---- Released
- Energy
- released
&



H
Y
e
H



o
- - - - - - - - -
- - - - - - - - -
Products
i
reactants
↑