Ea or k from Arrhenius Plot Info

Question

For the gas phase decomposition of difluoroperoxide,

F₂O₂F₂ + O₂

the rate constant has been determined at several temperatures. When ln k in s^-1 is plotted against the reciprocal of the Kelvin temperature, the resulting linear plot has a slope of -8.71×10³ K and a y-intercept of 29.4.

The activation energy for the gas phase decomposition of difluoroperoxide _____ is kJ/mol.

Answer 1

The Arrhenius equation has the form k = Ae-^Ea/RT

Rearranged to the form of y = mx + b (straight line) we have... ln k = -Ea/R (1/T) + ln A

The slope of the line = -Ea/R

slope = -8.71x10³

-8.7x10³ K = -Ea/8.314 J/Kmol

Ea = 7.23x10⁴ J/mol = 72.3 kJ/mol