Question

Calculate the value of standard enthalpy change for the sublimation of solid iodine at 25°C. The molar heat capacity of iodine (s) is 54.44 J/mol·K and its molar entropy of sublimation is 62.43 J/mol·K. The standard entropy of formation of iodine (s) is 62.80 J/mol·K.

Answer 1

To calculate the standard enthalpy change for the sublimation of solid iodine at 25C, we can use the Clausius-Clapeyron equation, which relates the enthalpy change of a phase transition to the temperature and entropy change of the process. The equation is as follows:H = T * Swhere H is the standard enthalpy change, T is the temperature in Kelvin, and S is the molar entropy change of the process.First, we need to convert the given temperature from Celsius to Kelvin:T = 25C + 273.15 = 298.15 KNext, we are given the molar entropy of sublimation  S  as 62.43 J/molK. Now we can plug these values into the Clausius-Clapeyron equation:H =  298.15 K  *  62.43 J/molK  = 18605.4 J/molThe standard enthalpy change for the sublimation of solid iodine at 25C is approximately 18,605.4 J/mol.