Chem: Integrated Rate laws pt1

2013-11-28 9:26 am

1.The first order reaction of conversion of Cyclopropane to propylene has a rate constant of 1.16 x 10-6 /s at 400°C. If the initial conc. of Cyclopropane is 1.00 x 10-2 mol/L, what will its concentration be 24.0 hr after the reaction begins?

2.The decomposition reaction 2N2O5 --------> 4NO2 + O2 is a first order reaction.A reaction was started at 45°C with an initial N2O5 conc. of 1.00 mol/L and after 3.00 hr its conc. had dropped to 1.00 x 10-2 mol/L. What is the half-life of N2O5 expressed in minutes at 45°C?

3.The rate constant for a particular reaction is 3.6 x 10-2 s-1. What is the half-life for this reaction?

4.The initial concentration of A, a reactant, is 0.20 M and the value of the rate constant is 0.14 M-1min-1. What is the rate of decomposition of A at the start of the reaction?

回答 (1)

用戶4366

2013-11-28 10:39 pm

✔ 最佳答案

1.from http://chemwiki.ucdavis.edu/Physical_Chemistry/Kinetics/Reaction_Rates/First-Order_Reactions

[A] =[A]oe−kt

[A] = (1X10⁻²)e^⁻(1.16X10⁻⁶)t

[A] = (1X10⁻²)e^⁻(1.16X10⁻⁶)(24X60X60)

[A] = 0.009046 mol/L

2. [A] =[A]oe−kt
1X10⁻² = (1)e−kt
-kt = -4.605
k(3X60) = 4.605
k = 0.0256
t12=ln2k
= (ln2)/0.0256 = 27.1 minutes

3,4 無得計 (唔知道 order of reaction)。

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