Write the chemical test to identify the following gases.
`NH_3`

Explanation

To identify the gas ammonia (NH₃), we can perform the following chemical test:

### Step-by-Step Solution:

1. **Gather Materials**: Obtain Nessler's reagent, which is a solution of potassium mercuric iodide (K₂HgI₄). This reagent is used specifically to test for the presence of ammonia or ammonium ions.

2. **Prepare the Sample**: If you have a gas sample suspected to be ammonia, ensure that it is in a suitable container or apparatus for testing. If you are testing a solution, ensure it is ready for the addition of the reagent.

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