For the given CaO$-$MgO system $($Figure $1),$ show the schematic MgO composition profile $=>D=\frac{1}{6}\frac{(2\mathrm{.}83{10}^{12}{)}^{-}}{2}6{10}^{13}$exp$(5)exp(-0\mathrm{.}079)$

$\{$:${10}^{-3})$

$=>D=643\mathrm{.}1710\frac{7}{2}=m^2$

Ans.

$D=3\mathrm{.}54{10}^{-39}\frac{m^2}{s}$

Long Answer Questions:

Q $1.)$

Initial temperalure $=2900C$

stauting composition of melt $=15$mol.Mgo.

No diffurion in solid a prefect mixing in liquid.

as a function of distance in a rod element at different stages of cooling when solidification

interface sweeps across the length. How much eutectic will form after complete

solidification? Assume the followings:

a$.$ Initial temperature is $2900\backslash$deg C$,$ starting composition of melt is $15$ mol$\%$ MgO.

b$.$ Heat is extracted unidirectionally through one of the shorter wall of the rod

element.

c$.$ No diffusion in solid and perfect mixing in liquid.