  In this publication we consider particle production at a future circular
hadron collider with 100 TeV centre of mass energy within the Standard Model,
and in particular their QCD aspects. Accurate predictions for these processes
pose severe theoretical challenges related to large hierarchies of scales and
possible large multiplicities of final state particles. We investigate scaling
patterns in multijet-production rates allowing to extrapolate predictions to
very high final-state multiplicities. Furthermore, we consider large-area QCD
jets and study the expectation for the mean number of subjets to be
reconstructed from their constituents and confront these with analytical
resummed predictions and with the expectation for boosted hadronic decays of
top-quarks and W-bosons. We also discuss the validity of
Higgs-Effective-Field-Theory in making predictions for Higgs-boson production
in association with jets. Finally, we consider the case of New Physics searches
at such a 100 TeV hadron-collider machine and discuss the expectations for
corresponding Standard-Model background processes.
