Final answer:
Silicon's key thermodynamic characteristics during phase transitions include its heat of fusion (46.4 kJ/mol), heat of vaporization (297 kJ/mol), and specific heat capacities in the solid (0.711 J/g°C) and liquid states (0.908 J/g°C). These values indicate the energy silicon absorbs or releases during phase changes and temperature rises.
Step-by-step explanation:
When considering the thermodynamic characteristics of silicon during its phase transitions, several factors are important: the heat of fusion (ΔHfus), the heat of vaporization (ΔHvap), and the specific heats of solid and liquid states.
The heats of fusion and vaporization represent the energy required for silicon to transition from solid to liquid (melting) and from liquid to gas (boiling), respectively, under a constant pressure of 1 atm.
For silicon at its melting point of 1410 °C, the heat of fusion is 46.4 kJ/mol.
This is the energy required to overcome the forces holding the solid structure together, causing it to become a liquid without a change in temperature.
During this transition, silicon absorbs 46.4 kJ/mol to change from a solid to a liquid.
Similarly, at its boiling point of 2355 °C, silicon has a considerably higher heat of vaporization at 297 kJ/mol, which is the energy required to break the intermolecular forces in the liquid state and turn it into a gas, again at a constant temperature.
The specific heat capacities of silicon in the solid and liquid states are 0.711 J/g°C and 0.908 J/g°C, respectively.
These values indicate the amount of heat needed to raise the temperature of one gram of silicon by one degree Celsius.
The higher specific heat capacity in the liquid state suggests that silicon can absorb more energy per gram as a liquid than as a solid before its temperature rises.
The following information is given for silicon at 1 atm: boiling point = 2355 °C Hvap(2355 °C) = 297 kJ/mol melting point = 1410 °C Hfus(1410 °C) = 46.4 kJ/mol specific heat solid = 0.711 J/g°C specific heat liquid = 0.908 J/g°C. Given this information, what are the key thermodynamic characteristics of silicon during its phase transitions, and how do they contribute to the behavior of silicon in terms of energy absorption and release?