order of reaction~

[ippie]

A reaction was found to have a half life that depended on the initial concentration of the reactant. For this reaction, which one of the following plots might be linear?

a. ln[A] vs. t
b. 1/[A] vs. t
c. both plots are linear.
d. neither plot is linear

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[poc91nc]

Well, we know that first order (choice a) is out of the question since it doesn't depend on initial concentration. Remember the equation for a first order process -2.3log(N/N') = kt initial concentrations will cancel out with substitution. Or you can just use 0.7/k = half life. Second order half life does depend on initial rate. I'd go with choice b which is the linear format for a second order reaction.

1/[A] - 1/[A]' = kt

 

[BodybldgDoc]

b? is that the correct answer?

 

[poc91nc]

use the expression for the second order reaction and solve for the half life to convince yourself. do the same for first order

 

[BodybldgDoc]

use the expression for the second order reaction and solve for the half life to convince yourself. do the same for first order

You are right. I was questioning the OP as to what the correct answer was because I would have guessed b as well.