When hydrogen sulfide (HS) is passed through nitric acid (HNO3), the product formed is an amorphous solid (S). Let's understand the reaction and the formation of the amorphous solid in detail.

1. Reaction:
HS + 2HNO3 → 2H2O + NO + S

2. Explanation:
- Hydrogen sulfide (HS) is a colorless gas with a strong odor of rotten eggs.
- Nitric acid (HNO3) is a strong acid used in various applications, including the production of fertilizers, explosives, and dyes.
- When HS is passed through nitric acid, it undergoes a redox reaction.
- Hydrogen sulfide is oxidized to sulfur, while nitric acid is reduced to nitric oxide (NO).
- Water (H2O) is also formed as a byproduct of the reaction.

3. Formation of Amorphous Solid:
- The product of the reaction between HS and nitric acid is an amorphous solid, which means it lacks a well-defined crystalline structure.
- Unlike crystalline solids, amorphous solids do not have a repeating pattern of atoms or molecules.
- The lack of a specific structure in amorphous solids gives them unique properties, such as transparency, lack of cleavage, and isotropic behavior.
- In the case of the reaction between HS and nitric acid, the amorphous solid formed is sulfur (S).
- Sulfur is usually found in its crystalline form, with various allotropes such as rhombic and monoclinic sulfur.
- However, when sulfur is formed as a product of the reaction between HS and nitric acid, it lacks a well-defined crystal structure and exists in the amorphous state.

In conclusion, when HS is passed through nitric acid, the product formed is an amorphous solid, specifically sulfur in its amorphous state. This amorphous sulfur lacks a well-defined crystalline structure and exhibits unique properties compared to its crystalline forms.