At 25 °C, the equilibrium partial pressures for the following reaction were found to be PA = 1.40 atm, PB = 8.90 atm, PC = 5.10 atm, and PD = 2.50 atm.
A(g)+2B(g) <-->C(g)+D(g)
What is the standard change in Gibbs free energy of this reaction at 25 °C.