How much energy in kilojoules is released when 25.0 g of ethanol vapor at 93.0 °C is cooled to -11.0 °C? Ethanol has mp = -114.1 °C, bp = 78.3 °C, ΔHvap = 38.56 kJ>mol, and ΔHfusio#n = 4.93 kJ>mol. The molar heat#capacity is 112.3 J>1K mol2 for the liquid and 65.6 J>1K vapor.

Phase changes refer to the transitions between solid, liquid, and gas states of matter, which occur at specific temperatures and pressures. In this question, ethanol transitions from vapor to liquid and then to solid as it cools. Understanding the enthalpy changes associated with these phase transitions, such as the heat of vaporization (ΔHvap) and heat of fusion (ΔHfusion), is crucial for calculating the total energy change.

Specific heat capacity is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius (or Kelvin). In this problem, the specific heat capacities for both the vapor and liquid phases of ethanol are provided, which are essential for calculating the energy change during the temperature change of ethanol vapor as it cools down to its melting point.

Energy calculations in thermodynamics involve using formulas to quantify heat transfer during physical and chemical processes. In this scenario, the total energy released when cooling ethanol includes contributions from cooling the vapor, condensing it to liquid, cooling the liquid, freezing it to solid, and finally cooling the solid. Each step requires applying the appropriate heat equations, considering mass, specific heat, and enthalpy changes.