Question

What is the standard enthalpy change for the sublimation of iodine (I2) at 25°C and 1 atm pressure, given that the standard enthalpy of fusion of iodine is 15.52 kJ/mol and the standard enthalpy of vaporization of iodine is 41.57 kJ/mol?

Answer 1

The standard enthalpy change for the sublimation of iodine  I2  can be calculated by adding the standard enthalpy of fusion and the standard enthalpy of vaporization. This is because sublimation is the process of a solid directly converting into a gas, which involves both fusion  solid to liquid  and vaporization  liquid to gas .Standard enthalpy change for sublimation = Standard enthalpy of fusion + Standard enthalpy of vaporizationStandard enthalpy change for sublimation = 15.52 kJ/mol + 41.57 kJ/molStandard enthalpy change for sublimation = 57.09 kJ/molSo, the standard enthalpy change for the sublimation of iodine  I2  at 25C and 1 atm pressure is 57.09 kJ/mol.