chemistry

The given reaction,
cyclopropane propene (isomerization),
follows first-order kinetics. The half-live was found to be 4.57 min at 796 K and rate constant was found to be 0.0328 s-1 at 850 K. Calculate the activation energy (in kJ/mol) for this reaction. Round your answer to 3 significant figures.

1. No guarantees, but here goes:

rate constant = C*e^(-Ea/RT)

A half life of 4.57 min = 274 s corresponds to a rate constant of ln2/274 = 2.53*10^-3 s^-1

Ea is the activation energy

0.0328 = C*e^(-Ea/850R)
0.00253 = C*e^(-Ea/796R)

12.96 = e^[-(Ea/R)(1/850 - 1/796)]

Solve for Ea. R = 8.317 J/mole*K

2.562 = (-Ea/R)*(-7.98*10^-5 K^-1)
Ea/R = 3.21*10^4 K
Ea= 2.67*10^5 J/mole
= 267 kJ/mole

posted by drwls

Similar Questions

1. Chemistry

Cyclopropane rearranges to form propene: CH2CH2CH2 --> CH2=CHCH3 by first-order kinetics. The rate constant is k = 2.74 x 10-3 s-1. The initial concentration of cyclopropane is 0.290 M. What will be the concentration of
2. AP Chemistry

For the reaction cyclopropane(g) → propene(g) at 500◦C, a plot of ln[cyclopropane] vs t gives a straight line with a slope of −0.00067 s−1 . What is the order of this reaction and what is the rate constant?
3. chemistry

The reaction, cyclopropane propene (isomerization), was observed to have rate constants k = 0.000213 s-1 at 477 °C and k = 0.0328 s-1 at 577 °C. What is the value of Ea expressed in kJ mol-1? Round your answer to 3 significant
4. Chemistry

heating cyclopropane (C3H6) converts it to propene (CH2=CHCH3). The rate law is first order in cyclopopane. If the rate constant at a particular temp is 6.22x10^-4 s^1 and the concentration of cyclopropane is held at .0300 mol/L,
5. chemistry

The isomerization reaction H3CNC(g) <=> H3CCN(g) was found to be first order in H3CNC. At 600 K, the concentration of H3CNC is 75% of its original value after 205 s. (a) What is the rate constant for this isomerization
6. Chemistry

Cyclopropane reacts to form propene in the gas phase. The reaction is first order in cylclopropane and has a rate constant of at 485 . If a 2.5 reaction vessel initially contains 724 of cyclopropane at 485 , how long will it take
7. Chem

Cyclopropane (C3H6) reacts to form propene (C3H6) in the gas phase. The reaction is first order in cylclopropane and has a rate constant of 5.87*10^-4 at 485degreesC. If a 2.5L reaction vessel initially contains 724 torr of
8. Chemistry

Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10-2 hr-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?
9. Physics

The activation energy for the isomerization ol cyclopropane to propene is 274 kJ/mol. By what factor does the rate of this reaction increase as the temperature rises from 256 to 297 oC? (The factor is the ratio of the rates.) A
10. reaction

conversion of cyclopropane to propene

More Similar Questions