The preexponential and activation energy for the diffusion o

The preexponential and activation energy for the diffusion of chromium in nickel are 1.1 x 10^ -4 m^2/s and 272,000 j/mol, respectively. At what temperature will the diffusion coefficient have a value of 1.2 x 10^14 m^2/s?

Solution

D = (D0)*e^(-Ea/(RT)).

Solving this for T gives T = -(Ea)/(R*ln(D/D0)). Now, simply plug in 1.1*10^(-4) for D0, 272000 for Ea, 2.2*10^(-14) for D, and 8.31 for R and you get your answer of 803.16 K. Converting it to °C gives
529.9 °C