In: Chemistry
The hydrolysis of 1-chloro-1-methyl cylcoheptane in 80% ethanol follows a first order rate equation. The values of the specific reaction rate constants are:
temp/C | 0 | 25 | 35 | 45 |
k/s-1 | 1.06x10-5 | 3.19x10-4 | 9.86x10-4 | 2.92x10-3 |
1. Plot Ln(k) against 1/T
2. Calculate the activation energy
3. Calculate the pre-exponential factor
K = A e-Ea/RT
lnK = lnK-Ea/RT
lnK = -Ea/RT +lnK
Y = mx+C
Plot Ln(k) against 1/T. A straight line does not passed through origine.Negative slope4
logk2/K1 = Ea/2.303R [1/T1 --1/T2]
log3.19*10-4/1.06*10-5 = Ea/2.303*8.314 [1/273 - 1/298]
1.4784*19.147 = Ea*(0.00366-0.003355)
Ea = 28.306/0.000305 = 92806.55Joules = 92.80655KJ
3.K = Ae-Ea/RT
1.06*10-5 = A e-92806.55/8.314*273
1.06*10-5 = Ae-40.88
1.06*10-5 = A*1.76*10-18
A = 1.06*10-5/1.76*10-18 = 6.02*1012 htz