Prob. $9(20$ pts$.)$ Mo in solid form contains $50\mathrm{.}9765$ E$24$ vacancies at the melting temperature $Tm=2620$ deg C$.$ Determine the energy of vacancy formation in $($a$)k\frac{J}{m}$ole and $($b$)$ the vacancy fraction at $75\%$ of the Tm in Kelvin. The density and AW are $10222k\frac{g}{c}u.m$ and $95\mathrm{.}94\frac{g}{m}$ole, respectively.

$Q=$