A copper block of mass 327.7 g is heated from 2.5 °C to an unknown temperature by the combustion of propane. This block is then put in immediate contact with an aluminum block of mass 419.2 g at a temperature of 6.8 °C . The two blocks reach equilibrium at 160.9 °C . Use 0.385 J/(g°C) for the specific heat of copper, 0.903 J/(g°C) for the specific heat of aluminum, and that the enthalpy for the combustion of propane is -2222 kJ . What is the amount of propane burned in moles? Report to 3 sig figs.