One mole of solid cr2 o3 at 2500 k is dissolved in a large volume of a liquid raoultian solution of al2 o3 and cr2 o3 , in which xcr2o3 = 0.2 and which is also at 2500 k. calculate the changes in enthalpy and entropy caused by the addition. the normal melting temperature of cr2 o3 is 2538 k, and it can be assumed that δsm, al2o3 δsm, cr2o3 =