question_answer 21)

    During the preparation of hydrogen chloride gas on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to                 (a) absorb the evolved gas                                          (b) moisten the gas                 (c) absorb moisture from the gas                              (d) absorb ions from the evolved gas                

Answer:

  (c) The role of calcium chlorideis to absorb moisture from the gas, because calcium chloride is a good dehydrating agent.