Question

Calculate the standard enthalpy change for the sublimation of iodine solid to iodine gas at 298 K with the following given data: - Standard enthalpy of fusion of iodine: 15.52 kJ/mol- Standard molar entropy of iodine solid: 62.7 J/K/mol- Standard molar entropy of iodine gas: 260.6 J/K/mol

Answer 1

To calculate the standard enthalpy change for the sublimation of iodine solid to iodine gas at 298 K, we can use the following equation:H_sublimation = H_fusion + H_vaporizationFirst, we need to find the enthalpy of vaporization  H_vaporization  using the given data. We can use the Clausius-Clapeyron equation:H_vaporization = T *  S_gas - S_solid where T is the temperature in Kelvin, S_gas is the standard molar entropy of iodine gas, and S_solid is the standard molar entropy of iodine solid.H_vaporization = 298 K *  260.6 J/K/mol - 62.7 J/K/mol H_vaporization = 298 K *  197.9 J/K/mol H_vaporization = 59042 J/molH_vaporization = 59.042 kJ/molNow we can calculate the enthalpy change for the sublimation:H_sublimation = H_fusion + H_vaporizationH_sublimation = 15.52 kJ/mol + 59.042 kJ/molH_sublimation = 74.562 kJ/molTherefore, the standard enthalpy change for the sublimation of iodine solid to iodine gas at 298 K is 74.562 kJ/mol.