  The equation of state of Chaplygin Gas is one of the simplest ways to
illustrate dark energy effects during the late time. Indeed, while one uses the
equation of state of Chaplygin Gas, the continuity equation gives specific
energy density which satisfies both deceleration (matter dominated) and
acceleration (dark energy epoch). In other words, for the earlier universe, the
energy density of whole energy-matter component behaves as matter era (baryonic
and dark matter) and treats such as dark energy in the standard model of
cosmology Lambda-CDM when a goes to infinity. Here, by using the general form
of F(R) gravity while the pressure of matter is non-zero, we show that even for
Einstein gravity (GR), one obtains a viable cosmological model with the same
energy density of Chaplygin Gas while Chaplygin Gas EoS is not used. Further,
we investigate cosmic evolution through two other different forms of F(R)
gravity and show general behavior of Hubble parameter, cosmological scale
factor and equation of state throughout cosmic time.
