Question

Name a gas which turns Nessler's reagent brown.

Answer 1

1. The gas that turns Nessler’s reagent brown is Ammonia gas $N{H}_3$ . This test is helpful during the detection of Nitrogen as an extra element in a given compound.
2. When fumes of ammonia gas are passed over the reagent, brown coloration in the fumes is observed. When the gas is directly passed into the reagent, a dark brown colored precipitate is formed. This is a confirmation test for the detection of Nitrogen in a given unknown compound.

Final Answer:

Ammonia gas.