Barium chloride (BaCl2) was added to about 2cm³ of an as queous solution, write precipitate was insoluble in excess dilute hydrochloric acid (HCl). What would be your inference and why? ?

The inference would be that the precipitate formed is likely to be barium sulfate (BaSO4). This is because barium sulfate is insoluble in water and dilute hydrochloric acid, which means that it would not dissolve in excess HCl. This reaction is commonly used in chemistry to test for the presence of sulfate ions in a solution.

Inference: The precipitate is likely barium sulfate (BaSO4).

Reasoning:

When barium chloride is added to an aqueous solution, it reacts with sulfate ions (SO4²⁻) to form barium sulfate. This reaction is represented by the following equation:

```
BaCl2(aq) + SO4²(aq) → BaSO4(s) + 2Cl⁻(aq)
```

Since the precipitate is insoluble in excess dilute hydrochloric acid, it cannot be a chloride salt of barium. This eliminates the possibility of barium chloride (BaCl2) or barium hydroxide (Ba(OH)2) being the precipitate.

The only common anion that forms an insoluble precipitate with barium ions is sulfate. Therefore, the precipitate is likely barium sulfate (BaSO4).