Final answer:
Hydrogen reacts with sulfur to form hydrogen sulfide with the chemical formula H₂S. Hydrogen sulfide is a weak diprotic acid that makes solutions basic when dissolved in water due to the formation of hydroxide ions.
Step-by-step explanation:
When hydrogen reacts with sulfur, the product formed is hydrogen sulfide, which is represented by the chemical formula H₂S.
This compound is well-known for its characteristic 'rotten egg' smell and is a toxic gas at room temperature. Hydrogen sulfide is a weak diprotic acid that can dissolve in water to form hydrosulfuric acid.
In water, it undergoes ionization in two stages: the first stage produces hydrogen sulfide ions (HS⁻), and the second stage yields sulfide ions (S²⁻).
The presence of these ions in solution makes the solution basic as they react with water to form hydroxide ions (OH⁻).
Thus, the correct answer to the given question is a) H₂S.