A copper-zinc alloy (85wt% Cu-10 wt% zinc) is coupled with pure copper (interfaced). The…

A copper-zinc alloy (85wt% Cu-10 wt% zinc) is coupled with pure copper (interfaced).
The diffusion couple is then heated to a temperature of 1000 degree celsius.

How long will it take for the concentration of zinc to reach 0.2%, 2.5 mm below the interferance?