Chemical model predictions to simulate gas temperature, density, and fractional abundances of HCN, HCO⁺, and electrons under moderately-dense conditions (n_H2 ∼ 10³ − 10⁴ cm⁻³). C-type shocks with shock velocities of 10, 20, 30, and 40 km s⁻¹ are considered. The pre-shock H₂ density is assumed to be 10³ cm⁻² for all cases. More details on the other assumed parameters are described in Sect. 6.2.