Gibbs energy and reaction favourability

At constant temperature and pressure, a negative Gibbs energy change indicates that a process is thermodynamically favourable in the forward direction. It does not tell you how quickly the process happens. A large activation barrier can make a favourable reaction very slow. The Gibbs energy change depends on enthalpy, entropy, temperature, and composition. At equilibrium it is zero for an infinitesimal net reaction. Distinguish thermodynamic direction from kinetic speed when interpreting an experiment.