1) The document discusses the thermal decomposition reaction of hydrogen iodide (HI). Experimental data on the rate constant (k) of the reaction at different temperatures is provided. 2) The complete rate equation for the reaction is derived. The Arrhenius equation is used to determine the activation energy (E) and pre-exponential factor (ko) by plotting the logarithm of k against the inverse of temperature. 3) The final rate equation determined is: -rHI = 4.06 x 1016 e-22,727/T CHI2 (mol/cm3.s)

1. SOAL
2.11 In the mid- nineteenth century the entomologist Henri Fabre noted that
French ants (Garden Variety) busily bustled about their businees on hot days
but were rather sluggish on cool days . Checking his results with Oregon ants,
I find
Running speed, m/hr 150 160 230 295 370
Temperature,oC 13 16 22 24 28
What activation energy represents this change in bustliness ?
Penyelesaian :
Dik :
Running speed, m/hr 150 160 230 295 370
Temperature,oC 13 16 22 24 28
Dit : Energi aktivasi (e) ?
Persamaan Linear : In S = −
𝐸
𝑅
1
𝑇
Speed (m/hr) In S (m/hr) T (oC) T (oK) 1/T x 10-3 (oK)
150 5,01 13 286 3,4965
160 5,07 16 289 3,4602
230 5,44 22 295 3,3898
295 5,69 24 297 3,3690
370 5,9113 28 301 3,3220
Plot In S vs 1/T

2. 3.31 The thermal decomposition of hydrogen iodide
2HI H2+ I2
Is reported by M. Bodenstein [Z. Phys. Chem., 29, 295 (1899)] as follows:
ToC 508 427 393 356 283
K, cm3/mol.s 0,1059 0,00310 0,000588 80,9 x 10-6 0,942 x 10-6
Find the complete rate equation for this reaction . Use Units of joules, moles, cm3,
and seconds.
Penyelesaian :
Dik :
ToC 508 427 393 356 283
K,
cm3/mol.s
0,1059 0,00310 0,000588 80,9 x 10-6 0,942 x 10-6
Dit : Laju reaksi (-rHI) ?
Persamaan Laju Reaksi : -rHI = k CHI
2
Persamaan Arrhenius : k = ko 𝑒
−
𝐸
𝑅𝑇 ..........(1)
Persamaan Garis Lurus : In k = In ko −
𝐸
𝑅
1
𝑇
..................(2)
Jadi, -rHI = ko 𝑒−
𝐸
𝑅𝑇 CHI
2
T (oC) T (oK) 1/T (K-1) k In k
508 781 0,00128 0,1059 - 1,6974
427 700 0,00143 0,00310 - 5,7764
393 666 0,001502 0,000588 - 7,4388
356 629 0,001510 80,9 x 10-6 - 9,4223

3. 283 546 0,001832 0,942 x 10-6 - 13,8753
Selanjutnya Plot Ink vs 1/T
Untuk mendapatkan nilai dari ko ambil dari data kedua
Dari persamaan (2) :
In k = In ko −
𝐸
𝑅
1
𝑇
= 5,7764 – 22727 (1/700) = 38,2439
ko = 𝑒38,2439
= 4,06 x 1016
Jadi, Selanjutnya dimasukkan ke persamaan 1 :
-rHI = ko 𝑒
−
𝐸
𝑅𝑇 CHI
2
= 4,06 x 1016 𝑒
−22,727
𝑇⁄
CHI
2 mol/cm3. s