$4\mathrm{.}3$ What is the energy of activation for the decomposition of di$-$tert$-$butyl per$-$

oxide $($Figure$4\mathrm{.}5)?$ For bis$(1-$hydroxy cyclohexyl$)$ peroxide?

FIGURE $4\mathrm{.}5$ Thermal stability of organic peroxides as indicated by time for decomposition of $50\%$ of the original charge $($half$-$life for first$-$order reaction$).($Data from Wallace and Tiernan Company, Lucidol Organic Peroxides, Lucidol Division, Wallace and Tiernan, Buffalo, NY$,1968.)$