a) For each pound (454g) of ammonium nitrate that exploded (products being nitrogen gas, oxygen gas, and water vapor) how many kJ of thermal energy were released and how many L of gas (measured at 1atm and 25degreeC) were formed? We know deltaHf for ammonium nitrate is -87.37 kcal/mol
b) The density of ammonium nitrate is 1.725g/cm^3. How many litres did the volume of the system increase when the pound of ammonium nitrate exploded?
For this process the balanced equationwill be: 2NH4NO3 = 2N2 + O2 + 4H2O. Delta H = -87.37 kJ/mol 454g / 80g/mol = 5.68 mols NH4NO3 N2: NH4NO3 = 4 : 4, so 5.68 mols of N2 formed. O2: NH4NO3 = 3 : 4 = x : 5.68, x = 4.26 mols O2 formed. So at 1 atm and 25 C, a mol of any ideal gas is 24.5 L. 24.5(5.68 + 4.26) = 243.5 Lb) The volume of NH4NO3 is 454g / 1.725g/mL = 263.2 mL = 0.2632 L The volume increased by a factor of 243.5 / 0.2632 = 925.1