rate Equations

[Bomikepa]

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can someone who is good with graphs and rates help me understand the rate equations?

Zero Order: [A] vs. time is linear (i.e., yields a straight line) with slope = -k
First Order: ln[A] vs. time is linear with slope =-k
Second Order: 1/[A] vs. time is linear with slope = k

i suck at graphs and i such even more once you start graphing with logs...natural logs...anti logs....

 

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Is this really mcat related? This is stuff that's covered in a physical chemistry 2 course.
Do you have a more specific question (you have to explain what the reaction is, ex: A->B)?

 

[Bomikepa]

yes its mcat related...dont we need to understand the graphs and learn the equations conceptrually?

 

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You should probably have a grasp of rate tables, finding the order with respect to a reactant, and finding the overall order. What you're thinking about is way out of scope for the mcat. Knowing the plot of the log function wouldn't hurt though.

This:
http://www.chem.ufl.edu/~itl/4411/lectures/lec_l.html

Here you can find a list of topics tested on the mcat:
https://www.aamc.org/students/applying/mcat/preparing/

 

[Bomikepa]

sweeet. i know how to detemine the orders from a table but i have in my notes i think its from tbr that we need to know these rate equations.

thanks for the log link..i need as much help as i can get when it comes to log graphs

 

[PlumbLine]

can someone who is good with graphs and rates help me understand the rate equations?

Zero Order: [A] vs. time is linear (i.e., yields a straight line) with slope = -k
First Order: ln[A] vs. time is linear with slope =-k
Second Order: 1/[A] vs. time is linear with slope = k

i suck at graphs and i such even more once you start graphing with logs...natural logs...anti logs....

Not sure if you already recognized this, but all of them can be related back to the standard y = mx + b equation that you learn on the first day of Algebra, where m is the slope, and b is the y-intercept.

The y = mx + b formula for each order reaction is derived from the rates, which can give you [A] at time t. Let [A]t equal [A] at time t, and [A]0 equal your starting [A].

Zero order: [A]t = -kt + [A]0

First order: ln[A]t = -kt + ln[A]0 (remember, [A]t = [A]0 * e^(-k/t), which this is derived from, is the same formula used for radioactive decay)

Second order: 1/[A]t = kt + 1/[A]0

But as the others have said, this is probably outside the scope of the mcat. Can't hurt to be able to recognize the basic trends though.