At standard pressure, ammonia melts at 195 K and boils at 240 K. If a sample of ammonia at standard pressure is cooled from 200 K down to absolute zero, what physical constants are needed to calculate the change in

enhtalpy?
I) the heat capacity of ammonia(s)
II) the heat capacity of ammonia(`)
III) the heat capacity of ammonia(g)
IV) the enthalpy of fusion of ammonia
V) the enthalpy of vaporization of ammonia

See your earlier post.

If the heat of fusion of ice is 335 J/g, how much heat is needed to melt 2.36 g of ice at 0.0°C?

To calculate the change in enthalpy when cooling a sample of ammonia from 200 K to absolute zero, several physical constants are needed. Here is a breakdown of the required constants:

I) The heat capacity of ammonia(s) (solid): This constant is needed to calculate the change in enthalpy during the cooling process when ammonia is in the solid state. The heat capacity of a substance determines the amount of heat energy required to raise its temperature by a certain amount. Since the substance is in the solid state, we need the specific heat capacity of ammonia in the solid phase.

II) The heat capacity of ammonia(ℓ) (liquid): This constant is required to calculate the change in enthalpy when ammonia is in the liquid state. It represents the amount of heat energy needed to raise the temperature of the liquid ammonia by a certain amount.

III) The heat capacity of ammonia(g) (gas): This constant is necessary to calculate the change in enthalpy when ammonia is in the gaseous state. It represents the amount of heat energy needed to raise the temperature of the gaseous ammonia by a certain amount.

IV) The enthalpy of fusion of ammonia: This constant is needed to calculate the change in enthalpy during the phase transition from solid to liquid, which is the melting process. The enthalpy of fusion represents the amount of heat energy required to convert a substance from the solid phase to the liquid phase at the melting point.

V) The enthalpy of vaporization of ammonia: This constant is required to calculate the change in enthalpy during the phase transition from liquid to gas, which is the boiling process. The enthalpy of vaporization represents the amount of heat energy needed to convert a substance from the liquid phase to the gas phase at the boiling point.

Overall, to accurately determine the change in enthalpy during the cooling process, you would need the heat capacity values for ammonia in its solid, liquid, and gas states, as well as the enthalpy of fusion and the enthalpy of vaporization of ammonia.