17.1 How Chemical Reactions Occur
-collision model
17.2 conditions that effect reaction rate
-activation energy(Ea)
-an increase in temperature speeds up molecules so the average collision is more energetic making it more likely for collisions to occur
Catalyst
Enzymes-
EX-carbonic anhydrase speeds up the following reaction to help prevent an excess accumulation of carbon dioxide in our blood
17.3 Heterogeneous reactions
Homogeneous reactions-
Heterogeneous reaction
EX
Factors that affect reaction rate
1.nature of reactants-
2.concentration-
3.temperature
4.surface area
17.4 equilibrium condition
Equilibrium
EX: rate of evaporation is exactly the rate of condensation
Chemical equilibrium-
EX
17.5 Chemical equilibrium
Example:
?why is it dynamic?
17.6 Equilibrium constant
aA + bB cC + dD
Equilibrium expression
K=[C]c[D]d
[A]a[B]b
-
?what can you tell me about the expression?
?what are the concentrations raised to?
Example:
equilibrium position
Example problem
The following reaction was performed with the following results in two DIFFERENT experiments
In equilibrium the following concentrations were noted:
Experiment 1
[SO3]=3.5M
[SO2]=1.5
[O2]=1.25
Experiment 2
[SO3]=.260M
[SO2]=.59M
[O2]=.045M
Calculate the equilibrium constant for both experiments:
?What does this experiment prove?
17.7 Heterogeneous equilibria
Homogeneous equilibria-
Heterogeneous equlibria-
?why?
Example problem
Deep Blue solid copper(II) sulfate is heated to drive off water vapor to form white solid copper(II)sulfate
Write the expression for K for this process:
17.8 LeChatelier’s principle
Example:
?What will happen with this reaction when more N2 is added and why?
Example: the following reactions represents hemoglobin + oxygen
?what happens to this reaction when we go up into a higher altitude where there is less oxygen?
Effects of volume change
?why?
Effects of temperature change
-
-exothermic reaction
-endothermic reaction
-treat energy as a reactant(in endothermic reactions) or as a product(in exothermic reactions) and predict the direction of the shift
?predict the shift in the following?
?predict the shift in the following?
Application of the equilibrium constant
Solubility equlibria
?what are some everyday applications to the phenomenon of solubility?
Ksp is the solubility product constant
Example:
Example:
The Ksp value for solid AgI(s) is 1.5 x 10-16 at 25 C. Calculate the solubility of AgI in water at 25 C
Ksp=1.5 x 10-16=[Ag+][I-]
-we assume that x moles dissolves to reach
equilibrium liter