Question

Calculate the amount of heat released when 0.5 moles of propane, C3H8, combust completely in oxygen gas, O2, according to the following balanced equation:C3H8(g) + 5O2(g) -> 3CO2(g) + 4H2O(l), ∆H = -2220 kJ/mol.

Answer 1

To calculate the amount of heat released, we can use the stoichiometry of the balanced equation and the given enthalpy change  H  for the reaction.The balanced equation tells us that 1 mole of propane  C3H8  reacts to release -2220 kJ of heat. We are given 0.5 moles of propane, so we can set up a proportion to find the heat released: Heat released  /  0.5 moles of C3H8  = -2220 kJ/mol /  1 mole of C3H8 Now, we can solve for the heat released:Heat released =  0.5 moles of C3H8  *  -2220 kJ/mol Heat released = -1110 kJSo, the amount of heat released when 0.5 moles of propane combust completely in oxygen gas is -1110 kJ. The negative sign indicates that the reaction is exothermic, meaning heat is released.