# The reaction, $Cr_2 O_3 + 2 AI \rightarrow Al_2 O_3 + 2 Cr$     $(\Delta G^{o} = - 421 kJ)$ is thermodynamically feasible as is apparent from the Gibbs energy value. Why does it not take place at room temperature?

$Cr_2 O_3 + 2 AI \rightarrow Al_2 O_3 + 2 Cr$