Question 26

[M.C.]

Dr. Ferdinand,

Is the equation "1/[At] = 1/[A0] + kt" the same as the one used in #24?

Thanks

[admin]

Definitely a test question, just like #24. Your score on this question does not count to your overall scaled score out of 15. There can be 1-2 test questions on the real MCAT. Only memorize the equations from this list: http://www.goldstandard-mcat.com/physics-equation-lists/

[kazuma]

I know this is a test question, but the solution seems to be more difficult than needed, bc the T1/2 equation for 2nd order reactions is simply; T1/2 = 1/k[Ao]
I learned that in chem 1

[asfino12217]

1/[At] = 1/[A0] + kt
this equation applies to other situations too right?

[nedaa.asba6809]

The rate equation for a chemical reaction is an equation that relates the reaction rate with concentrations or pressures of reactants and constant parameters.
For general reactions
A+B →C
The reaction rate = k(t) [A]m [B]n, where k(t) is the rate constant.
Now in the case when the differential equation is integrated it gives an equation that is usually called “integrated zero- order rate law”.
[A]t = -k(t) + [A]o where [A]t is the concentration at a particular time, and [A]o is the initial concentration.
For a zero- order reaction the half- life is given by t_(1/2)= 〖[A]〗_o/2k.
In our case, we are dealing with a second order reaction in the form of
r=k 〖[A]〗^2,or r=k[A][B]
then the integrated second- order rate law is given by
1/([A])=k(t)+ 1/〖[A]〗_o

[admin]

Bump.