  We present a model of the early chemical composition and elemental abundances
of planetary atmospheres based on the cumulative gaseous chemical species that
are accreted onto planets forming by core accretion from evolving
protoplanetary disks. The astrochemistry of the host disk is computed using an
ionization driven, non-equilibrium chemistry network within viscously evolving
disk models. We accrete gas giant planets whose orbital evolution is controlled
by planet traps using the standard core accretion model and track the chemical
composition of the material that is accreted onto the protoplanet. We choose a
fiducial disk model and evolve planets in 3 traps - water ice line, dead zone
and heat transition. For a disk with a lifetime of 4.1 Myr we produce two Hot
Jupiters (M = 1.43, 2.67 M$_{\rm Jupiter}$, r = 0.15, 0.11 AU) in the heat
transition and ice line trap and one failed core (M = 0.003 M$_{\rm Jupiter}$,
r =3.7 AU) in the dead zone. These planets are found with mixing ratios for CO
and H$_2$O of $1.99\times 10^{-4}$, $5.0\times 10^{-4}$ respectively for both
Hot Jupiters. Additionally for these planets we find CO$_2$ and CH$_4$, with
mixing ratios of $1.8\times 10^{-6}\rightarrow 9.8\times 10^{-10}$ and
$1.1\times 10^{-8}\rightarrow 2.3\times 10^{-10}$ respectively. These ranges
correspond well with the mixing ratio ranges that have been inferred through
the detection of emission spectra from Hot Jupiters by multiple authors. We
compute a carbon-to-oxygen ratio of 0.227 for the ice line planet and 0.279 for
the heat transition planet. These planets accreted their gas inside the ice
line, hence the sub-solar C/O.
