How many of the given statements are true for potash alum.
(1) it is a white crystalline solid
(2) it swells up on heating
(3) it imparts a golden yellow colour to the bunsen flame
(4) An aqueous solution of the above given a white gelatinous precipitate with `BaCl_(2)` solution soluble only in concentrated sulphuric acid.
(5) An aqueous solution of the above given a white gelatinous precipitate on treatment with `NH_(4)OH`. Which dissolves in aqueous `NaOH` in excess and reappears, On boiling with concentrated `NH_(4)Cl` solution.
(6) It gives a yellow precipitate with Cobalt nitrile solution.
(7) White precipitate in `5^(th)` state can also be obtained by passing `H_(2)S` gas in aqueous solution of the above.

Explanation

To determine how many of the given statements about potash alum are true, we will evaluate each statement one by one based on the information provided in the video transcript.

### Step-by-Step Solution:

1. **Statement 1: It is a white crystalline solid.**
- **Evaluation:** Potash alum (K₂SO₄·Al₂(SO₄)₃·24H₂O) is indeed a white crystalline solid.
- **Conclusion:** True.

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