The density and viscosity of aqueous solutions of 2-(1-piperazinyl)-ethylamine (PZEA) as well as the Henry's law constants and diffusivity of N2O in these solutions were measured at temperatures in the range (298 to 323) K at atmospheric pressure of 0.1 MPa. The mass fractions of PZEA used were (0.0108 to 0.158). The "N2O analogy" was used to estimate the Henry's law constants and diffusivity of CO2 in aqueous PZEA solutions. The experimental density, viscosity, Henry's law constants, and diffusivity data are correlated as a function of temperature and concentration of amine.