Ammonia gas is dried by

Options

A. `CaO`
B. Conc.`H_(2)SO_(4)`
C. `P_(4)O_(10)`
D. Anhydrous `CaCl_(2)`

Answer

1

Explanation

The moisture present in ammonia is removed by passing it through a glass tower packed with quick lime, `CaO`. For drying of ammonia gas, the common dehydrating agents like conc. `H_(2)SO_(4)` or anhydrous calcium chloride or phosphorus pentoxide can’t be used as these react with ammonia.
`2NH_(3)+H_(2)SO_(4)rarrunderset("Ammonium sulphate")((NH_(4))_(2)SO_(4))`
`CaCl_(2)+8NH_(3)rarrunderset("complex")(Cacl_(2).8NH_(3))`
`P_(2)O_(5)+3H_(2)Orarr2H_(3)PO_(4)`
`3NH_(3)+H_(3)PO_(4) rarr (NH_(4))_(3)PO_(4)`
`bar(P_(2)O_(5)+3NH_(3)+3H_(2)O rarr underset("Ammonium phosphate")(2(NH_(4))_(3)PO_(4)))`
For drying, quick lime `(CaO)` is used as it does not react with `NH_(3)` but reacts readily with moisture.
`CaO+H_(2)O rarr Ca(OH)_(2)`