Question

Calculate the heat required to sublime 34.5 g of dry ice (solid CO2) at a constant temperature and pressure, given that the heat of sublimation of CO2 is 25.2 kJ/mol.

Answer 1

To calculate the heat required to sublime 34.5 g of dry ice, we first need to determine the number of moles of CO2 present. The molar mass of CO2 is:C: 12.01 g/molO: 16.00 g/molCO2: 12.01 +  2  16.00  = 44.01 g/molNow, we can find the number of moles of CO2:moles = mass / molar massmoles = 34.5 g / 44.01 g/mol = 0.784 molNext, we can use the heat of sublimation  25.2 kJ/mol  to calculate the heat required to sublime the given amount of dry ice:heat = moles  heat of sublimationheat = 0.784 mol  25.2 kJ/mol = 19.76 kJTherefore, the heat required to sublime 34.5 g of dry ice is approximately 19.76 kJ.