Chemical Reaction Review
Generic Format of reaction
A + B
Reactants
→
C + D
Products
5 different types of chemical reactions:
1. _______________________
2. _______________________
3. _______________________
4. _______________________
5. _______________________
Collision Requirements
Requirement #1:
2HCl + Mg → MgCl2 + H2
____________________________________________
Wrong Orientation
2 Types of Collisions:
1. _______________________
2. _______________________
Correct Orientation
1. Effective Collision
2. Ineffective Collisions
Requirement #2:
___________________________________________________________________
___________________________________________________________________
Activation Energy

The concept of ___________________ - an energy barrier that must be
overcome for a __________________________to occur.

Entities must reach this _____________________________________________.

The _____________________ - which supplies the activation energy - may be in
the form of __________________________________

In other words, there is a minimum amount of energy required for reaction: the
_______________________________

Just as a ball cannot get over a hill if it
does not roll up the hill with enough
energy, a reaction cannot occur unless
the molecules possess
______________________ to get over
the activation energy barrier.
Endothermic Activation Energy
Exothermic Activation Energy
The ____________________________ the minimum amount of energy required
to initiate a chemical reaction.
Example #1
H2(g) + I2(g) → 2 HI(g)
ΔrH° = + 53.0 kJ
___________________________ between atoms or ions requires energy, making it an
_____________________ process.
__________________________ is the energy required to break a chemical bond. The
stronger the bond, the greater the energy needed to break it.
________________________ between atoms or ions _________________, making it an
___________________ process.
Bond energy is also the energy _________________________________________. The
____________________ the bond, the _________________ the energy released.
Bond Energies
-
Bond energies can be used to convey __________________________
-
Bond Energy is the amount of _________________________________________
-
Can show ____________________ or ____________________ reactions
Endothermic Reactions
In any endothermic reaction, the energy required to break bonds (2 O─H bonds in H2O)
is greater than the energy released when bonds are formed (O═O and H─H).
Exothermic Reactions
In any exothermic reaction, the energy required to break bonds (H─H and Cl ─Cl) is less
than the energy released when bonds are formed (H─Cl).
Example of energy change in Formation of HCl
All together there are 4 methods to predict or explain enthalpy changes:
1. ________________________________________________________________________
________________________________________________________________________
2. ________________________________________________________________________
________________________________________________________________________
3. ________________________________________________________________________
________________________________________________________________________
4. ________________________________________________________________________
________________________________________________________________________
Summary:
1. ________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
A catalyst is a substance that increases the rate
of a chemical reaction without being consumed
in the overall process.