The NH4 flame test is a specific method used in chemical experiments to detect ammonia salts. This test method is to determine whether it contains ammonia ions (NH4+) by observing the color of ammonia salt in the flame. The following are the steps to perform NH4 flame test:
1. **Preparation of samples**: First, it is necessary to prepare compound samples that may contain ammonia ions, such as ammonia water (a solution formed by dissolving ammonia gas in water), ammonia salt, etc. Make sure the sample is clean and pure to avoid the influence of other substances on the test results.
2. **Flame Test**: Place an appropriate amount of sample in an anhydrous flame-resistant cup (also called an observation cup).
3. **Ignite the sample**: Heat the sample with a flame. During heating, observe the color of the flame.
4. **Observe the flame color**: If the sample contains ammonia ions (NH4+), the flame will show a specific color after heating. The ammonia ions of the ammonia salt excite electrons when burned in a flame, producing specific spectral colors.
**Note**: The color observed by NH4 flame test is usually orange-yellow or yellow, but if there are other substances, the color may be shifted.
5. **Record the result**: Observe and record the flame color for subsequent analysis and identification.
Note that proper safety measures should be taken such as wearing lab coats, goggles, etc., when performing chemical experiments. If you do not have laboratory conditions or experience, do not attempt any chemical experiments to avoid danger.