Question

The following is a quote from an article in the August 18, 1998, issue of The New York Times about the breakdown of cellulose and starch: "A drop of 18 degrees Fahrenheit [from 77 ^\circ {\rm F} to 59 ^\circ {\rm F}] lowers the reaction rate six times; a 36-degree drop [from 77 ^\circ {\rm F} to 41 ^\circ {\rm F}] produces a fortyfold decrease in the rate."Assuming the value of E_a calculated from the 36-degree drop and assuming that the rate of breakdown is first order with a half-life at 25 ^\circ {\rm C} of 2.7 years, calculate the half-life for breakdown at a temperature of -15 ^\circ {\rm{C}}.