Answer:
Explanation:
Considering the relation of the equilibrium vacancy concentration ;
nv/N = exp (-ΔHv/KT)
Where T is the temperature at which the vacancy sites are formed
K = Boltzmaan constant
ΔHv = enthalpy of vacancy formation
Rearranging the equation and expressing in term of the temperature and plugging the values given to get the temperature. The detailed steps is as shown in the attached file