The diffusion coefficients for species a in metal b are given at two temperatures:
t (°c) d (m2/s) 1030
6.69 × 10-17 1290
6.56× 10-16
(a) determine the value of the activation energy qd (in j/ j/mol
(b) determine the value of m2/s (use scientific notation.)
(c) what is the magnitude of d at 1180°/s .

a) 149 kJ/mol, b) 6.11*10^-11 m^2/s ,c) 2.76*10^-16 m^2/s

Explanation:

Diffusion is governed by Arrhenius equation

I will be using R in the equation instead of k_b as the problem asks for molar activation energy

I will be using

and

°C + 273 = K

here, adjust your precision as neccessary

Since we got 2 difusion coefficients at 2 temperatures alredy, we can simply turn these into 2 linear equations to solve for a) and b) simply by taking logarithm

So:

and

You might notice that these equations have the form of  

You can solve this equation system easily using calculator, and you will eventually get

After you got those 2 parameters, the rest is easy, you can just plug them all   including the given temperature of 1180°C into the Arrhenius equation

And you should get D = 2.76*10^-16 m^/s as an answer for c)