Hydrogen sulfide, H₂S, is a toxic gas responsible for the odor of rotten eggs. The solubility of H₂S in water at STP is 0.195 M. What is the Henry’s law constant of H₂S at 0 °C? What is the solubility of H₂S in water at 0 °C and a partial pressure of 25.5 mm Hg?

Henry's Law states that the amount of gas that dissolves in a liquid at a given temperature is directly proportional to the partial pressure of that gas above the liquid. This relationship can be expressed mathematically as C = kH * P, where C is the concentration of the gas in the liquid, kH is the Henry's law constant, and P is the partial pressure of the gas.

Solubility refers to the maximum amount of a substance that can dissolve in a solvent at a specific temperature and pressure. For gases, solubility is influenced by factors such as temperature and pressure, with higher pressures generally increasing solubility. In the case of H₂S, its solubility in water can change with temperature and the partial pressure of the gas.

Standard Temperature and Pressure (STP) is a reference point used in chemistry, defined as 0 °C (273.15 K) and 1 atm pressure. At STP, the behavior of gases can be predicted using the ideal gas law, and it serves as a baseline for comparing the solubility and other properties of gases in different conditions. Understanding STP is crucial for calculating changes in solubility and gas behavior.