Question

Which of the following equations or inequalities for the change in free energy, Δg, for the evaporation of water is correct if the partial pressure of H₂O(g) is 1atm? Remember that Δg°rxn>0 for this process.

Answer 1

The equation for the change in free energy for the evaporation of water when the partial pressure of H₂O(g) is 1atm is: Δg = Δg°rxn + RT ln(PH₂O/1atm)

Step-by-step explanation:

The correct equation for the change in free energy, Δg, for the evaporation of water when the partial pressure of H₂O(g) is 1atm is:

Δg = Δg°rxn + RT ln(PH₂O/P°)

Where Δg°rxn is the standard change in free energy, R is the gas constant, T is the temperature in Kelvin, PH₂O is the partial pressure of water, and P° is the standard pressure. In this case, since the evaporation of water is nonspontaneous under standard conditions, Δg°rxn is positive. Therefore, the equation would be:

Δg = Δg°rxn + RT ln(PH₂O/1atm)

Where 1atm is the standard pressure.