Assignment:
Chlorine gas can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid:
MnO2(s) + 4HCl(aq) --> MnCl2(aq) + 2H2O(l) + Cl2(g)
How much MnO2 should be added to excess HCl to obtain 275mL of chlorine gas at 5.0C and 650 mmHg?