*Pengertian Laju reaksiPengukuran LajuPenentuan Hk. Laju Pengaruh Temperatur pada Laju reaksiMekanisme ReaksiCatalysis

Kinetika KimiaStudi/kajian tentang laju reaksihttp:// fpmipa.upi.edu/

*Rate Law; Integration form[A] - [A]0 = -kt Plotting [A] vs. t gives a straight line with slope = -k.[A] = [A]0 - kt. Orde 0A produk

*First Order Reaction; Integrationn = 1 (first order)[A] = [A]0 e-ktA produk

*First Order Reaction; Integrationn = 1 (first order)[A] = [A]0 e-ktA produkIntegrated form of the 1st order rate expressiony = mx + c

*Kinetika Orde dua; bentuk integrasiKinetika Orde 22A produk Hukum laju: dA/dt = k[A]2tt

*Kinetika Orde dua; bentuk integrasiKinetika Orde 22A produk

*2nd Order Rate Laws 5.2The most prominent difference between 1st and 2nd orders is the rate at low concentration of A, much slower for 2nd order2nd order decay processes die out long before they would have if they were 1st order decays,

especially important to the atmosphere, as many pollutants disappear by 2nd order laws

*Contoh SoalData reaksi dimerisasi 2A A2 suatu senyawa nitril oksida, ditunjukan pada tabel berikut:[A]/(mmol/L)68,050,240,333,128,422,3 18,714,5t/min04080120160240300420Tentukan orde reaksinya, dengan metode yang telah di pelajari!

*Kinetika Orde dua; bentuk integrasiBentuk lain dari reaksi orde 2 adalah r = k[A][B].More difficult to integrate !!!Untuk Reaksi: aA + bB produkPersamaan ini memiliki 3 variable: [A], [B], dan t

*Kinetika Orde dua; bentuk integrasiSupaya persamaan dapat diintegrasi [B] harus dieliminasi dengan menghubungkannya dg [A]

*Kinetika Orde dua; bentuk integrasi

*Penentuan Hukum Laju Cara Waktu paruhBerlaku untuk persamaan laju r = k[A]n

Orde 0 [A] = [A]0 - kt. Substitusi t dengan t dan [A] dengan [A]0 [A]0 = [A]0 kt1/2

*Penentuan Hukum Laju Cara Waktu paruhOrde 1 Substitusi t dengan t dan [A] dengan [A]0

*Penentuan Hukum Laju Cara Waktu paruhOrde 2 Substitusi t dengan t dan [A] dengan [A]0

*Penentuan Hukum Laju Cara Waktu paruhUntuk reaksi orde n:Untuk [A] = [A]0 dan t = t1/2

*Experimental Determination of Rate LawThis reaction order obtained is called pseudo- orderIsolation Method:All reactant is made excessive, except a reactant under investigationFor the reaction: mA + nB productIf A and B are dilutes solution: r = k[A]x[B]yIf the reaction is proceed in excess of B: r = k[A]x The various pseudo- orders can be put together to give the overall order.

*Determination of Rate Law The rate is measured at the beginning of reaction with some variations in reactant initial concentrations:Initial Rate Methods: Exercise: For the reaction 2A + B + C product, the initial reaction as a function of initial concentration is shown as follow (co=1mol/dm3):Expt. nr1234[A]o/co0,200,600,200,60[B]o/ co 0,300,300,900,30[C]o/ co 0,150,150,150,450100 ro/ (co /s)0,601,815,381,81

*Contoh soal (1)Dekomposisi fasa gas asetaldehid telah dipelajari pada temperatur 791 K. Hasil pengukuran dari dua percobaan adalah: Konsentrasi awal/(mol/L) 9,72 x 10-34,56x10-3Waktu paruh/detik328572Tentukan orde reaksi dan konstanta laju reaksinya!

*Contoh soal (1)Untuk reaksi A + B C + D, experimen dengan:[A0] = 400 mmol/L, dan [B0] = 4 mmol/L menghasilkan datat/s 0120240360~[C]x101/mmol.L-102,003,003,54,00Pada [A0] = 4 mmol/L, dan [B0] = 400 mmol/L menghasilkan datat/s 069206485~[C]x101/mmol.L-102,003,003,54,00Tentukan hukum laju dan konstanta laju

*Exercise E7.6The half-life of a substrate in a certain enzyme-catalyzed first order reaction is 138 s. How long is required for the initial concentration of substrate, which was 1.28 mmol/L, to fall to 0.040 mmol/L?