1. Appearance: Ammonium bifluoride is a colorless crystalline solid or granular powder.

2. Solubility: Ammonium bifluoride has good solubility in water, and the solution is weakly acidic.

3. Acidic: Ammonium bifluoride can release hydrogen fluoride gas in humid air.

The main uses of ammonium bifluoride are as follows:

1. As an etching agent and degumming agent: Ammonium hydrogen fluoride has strong etching and stain removal capabilities, and is commonly used in the etching process in semiconductor manufacturing and glass industry.

2. Preparation of metal fluoride: Ammonium bifluoride can be used to prepare fluoride compounds of other metals, such as sodium fluoride, aluminum fluoride, etc.

3. Chemical analysis: Ammonium bifluoride can be used as an analytical reagent to detect the presence and concentration of certain metal ions.

4. Laboratory use: Ammonium bifluoride can be used as a reagent in the laboratory, such as an indicator for acid-base titration.