Question

A certain reaction has an activation energy of 66.0 kJ/mol and a
frequency factor of *A*1 = 8.30×10^{12} M−1s−1 .
What is the rate constant, *k*, of this reaction at 27.0 ∘C
?

An unknown reaction was observed, and the following data were collected:

T(K) |
k( M−1⋅s−1) |

352 | 109 |

426 | 185 |

Determine the activation energy for this reaction.

Answer #1

1)

Given:

T = 27.0 oC

=(27.0+273)K

= 300.0 K

A = 8.3*10^12 M-1.s-1

Ea = 66.0 KJ/mol

= 66000.0 J/mol

R = 8.314 J/mol.K

use:

K = A*e^(-Ea/RT)

= 8.3*10^12*e^(-66000.0/(8.314*300.0))

= 8.3*10^12*e^(-26.4614)

= 8.3*10^12*3.221*10^-12

= 26.73 M-1.s-1

Answer: 26.7 M-1.s-1

2)

Given:

T1 = 352 K

T2 = 426 K

K1 = 1.09*10^2 M-1.s-1

K2 = 1.85*10^2 M-1.s-1

use:

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

ln(1.85*10^2/1.09*10^2) = ( Ea/8.314)*(1/352 - 1/426)

0.529 = (Ea/8.314)*(4.935*10^-4)

Ea = 8912 J/mol

Ea = 8.9124 KJ/mol

Answer: 8.91 KJ/mol

A certain reaction has an activation energy of 64.0 kJ/mol and a
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?
Express your answer with the appropriate units. Indicate the
multiplication of units explicitly either with a multiplication dot
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Part B
An unknown reaction was observed, and the following data were
collected:
T
(K )
k
(M−1⋅s−1 )
352
109
426
185
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__________________________________________________
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