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Questions
Dry HCl gas does not change the colour of dry blue litmus paper. Why?
Why does dry HCl gas not change the colour of the dry litmus paper?
Solution
The only thing that affects a substance's pH are its ions. In the presence of water, HCl produces hydrogen ions. In the absence of water, the H+ ion and HCl molecules cannot be separated. Because dry HCI lacks H+ ions, it does not exhibit the characteristics of an acid.
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