Question

ARRHENIUS EQUATION CALCULATIONS The activation energy for the gas phase decomposition of dinitrogen pentoxide is 103 kJ. N2O52 NO2 + 1/2 O2 The rate constant at 319 K is 5.59×10-4 /s. The rate constant will be 6.37×10-3 /s at ______ K.

PART 2 The activation energy for the gas phase isomerization of isopropenyl allyl ether is 123 kJ. CH2=C(CH3)-O-CH2CH=CH2CH3COCH2CH2CH=CH2 The rate constant at 432 K is 2.68×10-4 /s. The rate constant will be______ /s at 474 K.

Answer 1

1)

Given:

T1 = 319 K

K1 = 5.59*10^-4 /s

K2 = 6.37*10^-3 /s

Ea = 103 KJ/mol

= 103000 J/mol

use:

ln(K2/K1) = (Ea/R)*(1/T1 - 1/T2)

ln(6.37*10^-3/5.59*10^-4) = (103000.0/8.314)*(1/319 - 1/T2)

2.4332 = 12388.7419*(1/319 - 1/T2)

T2 = 340 K

Answer: 340 K

2)

Given:

T1 = 432 K

T2 = 474 K

K1 = 2.68*10^-4 /s

Ea = 123 KJ/mol

= 123000 J/mol

use:

ln(K2/K1) = (Ea/R)*(1/T1 - 1/T2)

ln(K2/2.68*10^-4) = (123000.0/8.314)*(1/432 - 1/474.0)

ln(K2/2.68*10^-4) = 14794*(2.051*10^-4)

K2 = 5.572*10^-3 /s

Answer: 5.57*10^-3 /s