Question

The rate constant of a first-order reaction is 0.0032 x 10^-4 L/mol *s at 640 K. If the activation energy is 176,406J/mol, calculate the temperature at which is rate constant is 0.0039 x10 ^-4 L/mol*s.

Show your work please.

Answer 1

First of all, this is a second order reaction. That is clear from the unit of the rate constant.

From, Arrhenius equation, we have a relationship between temperature and rate constant

ln (k1/k2) = (Ea/R) ((1/T2)-(1/T1))

k1 and k2 are rate constants at two temperatures.

k1 = 0.0032 x 10^-4 L/s.mol

k2 = 0.0039 x10 ^-4 L/s.mol.

Ea = activation energy = 176,406J/mol

T1 = 640 K

R = gas constant =8.314

putting values in the above equation

ln (0.8205) = (21217.94) ((1/T2)-0.00156)

-0.1978/21217.94 = (1/T2)-0.00156

-0.0000093 = (1/T2)-0.00156

(1/T2) = 0.00155

T2 = 645.16 K

answered by: anonymous