Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl (aq), as described by the chemical equation
MnO₂ (s) + 4HCl (aq) ⟶ MnCl₂ (aq) + 2H₂O (l) + Cl₂ (g)
How much MnO₂ (s) should be added to excess HCl (aq) to obtain 115 mL Cl₂ (g) at 25 °C and 805 Torr?