The following are pertaining to the laboratory preparation of hydrogen chloride gas.
Name the drying agent used and justify your choice.
The drying agent used in the laboratory preparation of hydrochloric acid is conc. sulphuric acid.
The other drying agents such as phosphorus pentoxide (P2O5) and quicklime (CaO) cannot be used because they react with hydrogen chloride.
2P2O5 + 3HCl → POCl3 + 3HPO3
CaO + 2HCl → POCl3 + 3HPO3