Give an example of a double salt.

Explanation

**Step-by-Step Solution:**

1. **Definition of Double Salt**:
- Double salts are formed by the combination of two different salts that crystallize together. They retain the identities of the individual salts when in solid form but lose their distinct properties when dissolved in water.

2. **Characteristics of Double Salts**:
- When double salts are in solid state, they exhibit the properties of the individual salts.
- Upon dissolution in a solvent, double salts dissociate into their constituent ions and lose their unique properties.
...