Penentuan Orde reaksi dan k Pengaruh Temperatur terhadap Laju Reaksi.

Presentasi berjudul: "Penentuan Orde reaksi dan k Pengaruh Temperatur terhadap Laju Reaksi."— Transcript presentasi:

1 Penentuan Orde reaksi dan k Pengaruh Temperatur terhadap Laju Reaksi

2 Persamaan Laju Reaksi Order ZeroFirstSecond Persamaan laju reaksi Hasil integrasi[A] 1 = [A] o – ktln [A] 1 – ln [A] o = – kt or log [A] 1 – log [A] o =

3 Grafik penentuan orde reaksi [A] t [A] 1 = [A] o – kt Orde nol k = -slope ln[A] t ln [A] 1 – ln [A] o = – kt Orde pertama k = -slope 1/[A] t Orde kedua k = slope

4 Serbuk antimon beraksi dengan briomin lebih cepat pada temperatur 75°C daripada pada 25°C Telur lebih cepat masak dalam air mendidih daripada dalam air dingin 75°C25°C

5 Pengaruh Tempratur terhadap Laju Reaksi Fraction of molecules with a given kinetic energy Kinetic energy T1T1 T2T2 T 1 > T 2 EaEa Svante Arrhenius

6 Dalam bentuk logaritma

7 ln k 1/T Slope = -Ea/R

8 EXAMPLE The specific rate constant, k, for the following first- order reaction is 9.16 x 10 -3 s -1 at 0.0°C. The activation energy of this reaction is 88.0 kJ/mol. Determine the value of k at 2.0°C. N 2 O 5  NO 2 + NO 3 EXAMPLE The specific rate constant, k, for the following first- order reaction is 9.16 x 10 -3 s -1 at 0.0°C. The activation energy of this reaction is 88.0 kJ/mol. Determine the value of k at 2.0°C. N 2 O 5  NO 2 + NO 3 Plan E a : 88,000 J/mol R : 8.314 J/molK k 1 : 9.16 x 10 -3 s -1 T 1 : 273 K T 2 : 275 K Question k 2 at T 2 : 275 K

9 Solution k 2 = 1.21 x 10 -3 s -1 Value k 2 at T 2 275 K is 1.21 x 10 -3 s -1

10 Exercises 1.The following data were obtained from a study of the decomposition of a sample of HI on the surface of a gold wire. (a) Plot the data to find the order of the reaction, the rate constant, and the rate equation. (b) Calculate the HI concentration in mmol/L at 600. s. t (seconds)[HI] (mmol/L) 05,46 2504,10 5002,73 7501,37

11 2. The gas-phase decomposition of ethyl iodide to give ethylene and hydrogen iodide is a first order reaction. C 2 H 5 I  C 2 H 4 + HI At 600. K, the value of k is 1.60 x 10 -5 s -1. When the temperature is raised to 700. K, the value of k increases to 6.36 x 10 -3 s -1. What is the activation energy for this reaction?

12 3.The rate constant for the decomposition of nitrogen dioxide 2NO 2  2NO + O 2 with a laser beam is 1.70 M -1 min -1. Find the time, in seconds, needed to decrease 2.00 mol/L of NO 2 to 1.25 mol/L