  We study flavor mixing and the axial anomaly in QCD at zero and finite
temperature. Using the instanton liquid model, we show that the strength of the
anomaly is essentially unchanged near the critical temperature for chiral
symmetry restoration. We demonstrate that nevertheless, chiral symmetry
restoration has important consequences for the eta and eta prime. In
particular, the strange and non-strange components of the eta unmix near T_c.
The anomaly does not affect the strange eta, so we expect a light purely
strange pseudoscalar meson near the phase transition.
