To calculate the heat required to sublime 30 grams of dry ice, we first need to determine the number of moles of CO2 present in 30 grams. The molar mass of CO2 is 12.01 g/mol C + 2 * 16.00 g/mol O = 44.01 g/mol.Number of moles = mass / molar massNumber of moles = 30 g / 44.01 g/mol = 0.6816 molNow, we can use the heat of sublimation to calculate the heat required:Heat required = number of moles * heat of sublimationHeat required = 0.6816 mol * 25.2 kJ/mol = 17.17 kJTherefore, the heat required to sublime 30 grams of dry ice at a constant pressure of 1 atm is approximately 17.17 kJ.