SciHawks

AP Chem: Kinetics exam on Monday covers all notes from and problem sets from the unit with emphasis on :

• Complete explanation of HOW each factor that can affect the rate of a reaction does so.
•  
• Explanation must be in terms of collision frequency, fraction of particles with proper orientation for an effective collision, fraction of molecules that meet or exceed the activation energy for an effective collision, and overall effective collision frequency. You should use made up numbers in your explanation.
•  
• Calculation of rate of reaction (from graphs or data) from rate of appearance or disappearance of products or reactants, respectively.
•  
• Determination of rate law, order of reaction overall, and for each reactant, from data table and from graphed data.
•  
• Assessing the plausibility of reaction mechanisms, after the rate law has been experimentally determined, and relating the rate law to the mechanism.
•  
• Determination and explanation of catalysts and intermediates in reaction mechanisms.
• Explanation/determination of catalysts and intermediates on energy/enthalpy diagrams.
•  
• Time-dependent rate law calculations (any order) from data tables, graphs, or time/concentration data.
•  
• Using the two versions of the Arrhenius equation to determine activation energy, frequency factor or rate constant at a second temperature, given graphs or data table of rate constant vs. inverse temperature, or given appropriate data.
• Knowledge/interpretation of any graphical representation of any order rate law.

As with all remaining topics in AP Chem, there are many discrete objectives, however, most of them are inter-related so that an understanding of one objective leads to an understanding of several other objectives. Also, even on somewhat quantitative topics such as kinetics, a qualitative understanding of the CAUSES of the formulas or phenomena is primary and ESSENTIAL.

In class today, we discussed the causes of the relationship among the variables in the Arrhenius equation.
We showed how to eliminate the frequency factor to come up with a derived Arrhenius equation in which we can predict the rate constant for a given reaction at a second temperature, given the rate constant at a different temperature.
We discussed the meaning of A, the frequency factor, and showed how to obtain the value from the ln A, y-intercept, on a graph of MANY data points showing the linear relationship between the ln of k and the INVERSE Kelvin temperature.

Bio- we finished up the human respiratory system, showing in detail how breathing is regulated via the nerve sensors in the medulla and aorta, which signal the diaphragm to contract, which causes air pressure differences between the air in the lungs and the external air.
We also discussed four diseases of the respiratory system in terms of cause and effect.