Question

Calculate the Heat of Sublimation of iodine (I2) if 20.0 grams of iodine sublimate at standard temperature and pressure (STP) from a solid to a gas phase absorbing 62.30 kJ of heat energy in the process.

Answer 1

To calculate the heat of sublimation of iodine  I2 , we need to determine the amount of heat energy required to convert 1 mole of iodine from solid to gas phase. First, we need to find the number of moles of iodine in 20.0 grams. The molar mass of iodine  I2  is 253.8 g/mol  2 x 126.9 g/mol .Number of moles = mass / molar massNumber of moles = 20.0 g / 253.8 g/molNumber of moles = 0.0788 molNow, we know that 0.0788 moles of iodine absorb 62.30 kJ of heat energy during sublimation. To find the heat of sublimation per mole, we can use the following equation:Heat of sublimation  kJ/mol  = Heat energy absorbed  kJ  / Number of moles  mol Heat of sublimation  kJ/mol  = 62.30 kJ / 0.0788 molHeat of sublimation  kJ/mol   790.4 kJ/molTherefore, the heat of sublimation of iodine  I2  is approximately 790.4 kJ/mol.