Question -
Answer -
The value of 
for the formation of Cr2O3 from Cr (−540 kJmol−1)is higher than that of Al2O3 from Al (−827 kJmol−1). Therefore, Al can reduce Cr2O3 to Cr. Hence, the reduction of Cr2O3 with Al is possible.
Alternatively,
Subtracting equation (ii) from(i), we have
As for the reduction reactionof Cr2O3 by Al is negative,this reaction is possible.