2021 · Q26
Which one of the following materials is present in a guard tube (drying tube) that is used for preparation of HCl gas?
General KnowledgeChemistry
- ACalcium chloride
- BCalcium bromide
- CCalcium iodide
- DCalcium fluoride
Explanation
A guard (drying) tube used in the laboratory preparation of HCl gas is packed with anhydrous calcium chloride, a hygroscopic substance that absorbs moisture from the gas stream. Calcium bromide, iodide and fluoride are not used as desiccants for this purpose.