Matakuliah
Tahun
Versi
: <<D0134>>/<<KIMIA INDUSTRI>>
: <<2006>>
: <<BARU>>
Pertemuan <<11>>
<< LAJU REAKSI>>
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• << TIK-12 >>
2
Outline Materi
• Materi 1 : Definisi Laju Reaksi
• Materi 2 : Rumus Laju Reaksi
• Materi 3 : Orde Reaksi
3
<<ISI>>
• Definisi Laju Reaksi adalah:
*berkurangnya konsentrsi reaktan per
satuan waktu => - ( Reaktan )
dt
*bertambahnya konsentrasi produk per
satuan waktu = > + ( produk )
dt
4
Rumus Laju Reaksi
• Reaksi A + B
C + D
• VA = -(A)/dt , VB = -(B)/dt
• VC = +(C ) /dt, VD = +(D)/dt
• Laju reaksi ditentukan oleh zat yang bereaksi,
oleh karena itu secara total rumus laju reaksi
menjadi :
• V =k.(A)x(B)y ; k = konstanta laju reaksi
•
x dan y = orde reaksi
5
•Initial Rates and Rate Laws
first get the reaction order from the data:
2x
2x
rate=k[NO]2[O2]1
4x
2x
this equation is
called the rate law
6
second get the reaction constant from the data:
rate
0.0024Ms 1
3
2 1
k


7
.
1
x
10
M
s
k
2
2
(0.015M ) (0.015)
[ NO] [O2 ]
note: units for k differ for each reaction! (Why?)
7
The rate law,
also called the differential rate law,
shows how
the reaction rate
depends on concentration.
The rate law
must be
determined
experimentally
8
example: determine the rate law for formation of I3AND determine the rate constant
-
expt [H2O2]init [I ]init initial rate
(M)
(M)
(M/s)
-4
1
0.100 0.100 1.15x10
2
3
4
0.100
0.200
0.200
0.200
0.100
0.200
2.30x10
-4
2.30x10
-4
4.6x10
-4
9