  Partial condensation of dust from the Solar nebula is likely responsible for
the diverse chemical compositions of chondrites and rocky planets/planetesimals
in the inner Solar system. We present a forward physical-chemical model of a
protoplanetary disc to predict the chemical compositions of planetary building
blocks that may form from such a disc. Our model includes the physical
evolution of the disc and the condensation, partial advection, and decoupling
of the dust within it. The chemical composition of the condensate changes with
time and radius. We compare the results of two dust condensation models: one
where an element condenses when the midplane temperature in the disc is lower
than the 50\% condensation temperature ($\rm T_{50}$) of that element and the
other where the condensation of the dust is calculated by a Gibbs free energy
minimization technique assuming chemical equilibrium at local disc temperature
and pressure. The results of two models are generally consistent with some
systematic differences of $\sim 10$\% depending upon the radial distance and an
element's condensation temperature. Both models predict compositions similar to
CM, CO, and CV chondrites provided that the decoupling timescale of the dust is
on the order of the evolution timescale of the disc or longer. If the
decoupling timescale is too short, the composition deviates significantly from
the measured values. These models may contribute to our understanding of the
chemical compositions of chondrites, and ultimately the terrestrial planets in
the solar system, and may constrain the potential chemical compositions of
rocky exoplanets.
