The G value for formation of gaseous water at 298 K and 1 atm is -278 kJ/mol. What is the nature of the spontaneity of formation of gaseous water at these conditions?
A. The reaction is never spontaneous.
B. The reaction is sometimes spontaneous.
C. The reaction is spontaneous.
D. The reaction may or may not be spontaneous.
When dG is negative the reaction is spontaneous.
To determine the nature of the spontaneity of a reaction, we need to consider the Gibbs free energy change (ΔG) for the reaction.
ΔG is related to the spontaneity of a reaction using the equation:
ΔG = ΔH - TΔS
where ΔH is the enthalpy change, ΔS is the entropy change, and T is the temperature in Kelvin.
In this case, the given value of -278 kJ/mol is ΔG. We need to determine the sign of ΔG to determine the nature of spontaneity.
If ΔG < 0, the reaction is spontaneous.
If ΔG > 0, the reaction is non-spontaneous.
If ΔG = 0, the reaction is at equilibrium and can go in either direction.
Since the given value of ΔG is negative (-278 kJ/mol), we can conclude that the reaction is spontaneous. Therefore, the answer is:
C. The reaction is spontaneous.