Question

HIR The following data show the rate constant of a reaction measured at several different temperatures. Use an Arrhenius plot to determine the activation barrier for the reaction. Express your answer using three significant figures. 150 ACQ* O ? Temperature (K) Rate Constant (s-1) 310 7.93x10-2 320 0.233 330 0.643 340 1.67 4.10 kJ mol-1 350 Submit Request Answer Part B Use an Arrhenius plot to determine the frequency factor for the reaction. Express your answer using two significant figures. IVO AQ o ? Submit Request Answer

Answer 1

Answer:

data is,

rate constant (k) temperature (T) 1/1 In(k) 0.0793 310 0.003226 -2.53452 0.233 320 0.003125 -1.45672 0.643 330 0.00303 -0.44161 1.67 340 0.002941 0.512824 4.1 350 0.002857 1.410987

As,

k = A exp(-Ea/RT)

where k = rate constant

A = frequency factor

Ea = activation energy

R = gas constant = 8.314 J/K-mol

T = temperature

so

ln(k) = A - (Ea/RT)

So slope of ln(k) vs 1/T is -Ea/R

so plot is,

In(k) -0.9.0028 0.0029 0.003 0.0031 0.0032 0.0033 y = -10705x + 31.996 R2 = 1 1/1

Here slope = -10705 = -Ea/R

Ea = 10705 x R = 10705 x 8.314 J/mol = 89001.37 J/mol = 89.001 kJ/mol = Ea

S activation energy of reation is,

Ea = 89.001 kJ/mol

From above,

ln A = intercept of line = 31.996

A = exp (31.996) = 7.86 x 1013

So

frequency factor = 7.86 x 1013