I am stuck on a problem in P. Chem. The question is below, but it asks to calculate the change in gibbs energy on water when the pressure changes and it assumes there is no volume change. I keep coming back to ΔG= V*(Pfinal-Pinitial) but my Prof. has added the mass density of water that I do not know what to do with or if it's a red herring. Can anyone point me in the right direction?
"Estimate the change in the Gibbs energy of 100 cm3 of water when the pressure acting on it is increased from 100 kPa to 500 kPa. The mass density of water is 0.997 g cm−3 . Assume that water is incompressible"