[Saionji]

1)Determine the rate constant k of the following first-order reactions, expressed as the rate of consumption of A:
a) A -> B, knowing that the concentration of A decreases to half its initial value in 1000s.
b) A -> B, knowing that the concentration of A decreases from 0.67 mol / L to 0.53 mol / L in the 25s.
c) 2A -> B + C, knowing that [A] 0 = 0, 153 mol / L and that after 115s = 0, 034 mol / L
I did ln[A]=ln[A]0 - kt, but for example letter a is : ln1/2=ln1 - k.1000 ? It is wrong...


2) At 400 ° C, the conversion of cyclopropane into propene has rate constant k = 1,16.10-6 s-1. If the initial concentration of cyclopropane is 0.01 mol / L, which is the concentration of propylene 10 days later, in mol / L? Give the answer in terms of e.
I did the same that the problem 1...

3) Is the reaction of equation A-> 2B. This reaction is first order with rate constant 0.02 min-1. A was added to a container to deform under the pressure of 725 mm Hg. After 140 min.
a) What is the partial pressure of A?
b) What is the total pressure?
 I did not understand how find pressure or how use [A]=[A]0. e^-kt


4) Prove that ln(k1/k2)=(Ea1-Ea2)/RT
I know that ln(k1/k2)=Ea/R(1/T2-1/T1), and I believe that is only some counts but I can not prove that even so.

* how can i use latex to write?

[Schrödinger]

1)Determine the rate constant k of the following first-order reactions, expressed as the rate of consumption of A:
a) A -> B, knowing that the concentration of A decreases to half its initial value in 1000s.
b) A -> B, knowing that the concentration of A decreases from 0.67 mol / L to 0.53 mol / L in the 25s.
c) 2A -> B + C, knowing that [A] 0 = 0, 153 mol / L and that after 115s = 0, 034 mol / L
I did ln[A]=ln[A]0 - kt, but for example letter a is : ln1/2=ln1 - k.1000 ? It is wrong...

The equation would be ln[A]/2=ln[A] - k.1000. [A]'s aren't needed, but just to make things clear
But what you've done seems correct to me. Why do you say it is wrong?

4) Prove that ln(k1/k2)=(Ea1-Ea2)/RT
I know that ln(k1/k2)=Ea/R(1/T2-1/T1), and I believe that is only some counts but I can not prove that even so.

Write the Arrhenius equation, then do a little math