In recent years, the study of fluctuations of conserved charges has received increasing attention: they turned out to be a promising tool to study the deconfinement phase transition of QCD, the existence of a critical point in the phase diagram and, more recently, the chemical freeze-out conditions in heavy-ion collisions (HICs). The study of the lower and higher order moments of particle distributions measured in HICs would be very useful to provide insight in the chemical freeze-out process. Results on the moments of net-charge and net-proton number have been presented by the STAR collaboration. I will present results on the chemical freeze-out parameters from combinations of such moments that can be calculated in a Hadron Resonance Gas (HRG) model. The HRG model can provide a link between first principles calculations from Lattice and experimental data. In the last part of the talk I will present a preliminary study on the issue of missing strange states in the hadronic spectrum starting from a comparison of observables sensitive to the strangeness content of hadrons obtained in the HRG and in Lattice.