What is importance of dry tests and it is applicable to which kind of substances ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Dry Tests**: Dry tests refer to qualitative analysis methods that are performed on solid samples without the use of solvents or liquids. These tests are crucial in identifying the presence or absence of specific ions or compounds in a sample.

2. **Importance of Dry Tests**:
- **Quick Information**: One of the primary advantages of dry tests is that they provide information in a short amount of time. This is particularly useful in laboratory settings where time efficiency is essential.
- **Presence or Absence of Substances**: Dry tests help determine whether certain substances are present or absent in a sample. This is fundamental in qualitative analysis as it guides further testing or analysis.
- **Modification of Weight Analysis**: Dry tests can modify and shorten weight analysis procedures. This means that the traditional methods of weighing and analyzing substances can be streamlined, making the process more efficient.
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