The entropy change at a high temperature T_X where aluminium is oxidized by oxygen is 335 JK^-1mol^-1 . The standard state entropy is -310.25 JK^-1mol^-1 . Calculate T_X if T_f = 900K and H_f = 10400 Jmol^-1 Al.

Given:

Cp = 105.19 JK¹mol¹ , Cp_O2 =31.6 JK¹mol¹ , Cp = 27.8 JK¹mol¹ and Cp_{Al} = 32.5 JK¹mol¹ .