The statement "if one quantity of gas will dissolve at one atmosphere of pressure, then three quantities of gas will dissolve at three atmospheres" refers to which principle?

The statement about the relationship between the amount of gas that can dissolve and the pressure it is under refers to Henry's Law. This principle states that the amount of a gas that dissolves in a liquid at a given temperature is directly proportional to the partial pressure of that gas above the liquid.

When you increase the pressure, as described in the statement, more gas molecules are pushed into the liquid, allowing for a greater quantity to dissolve. Thus, if one quantity of gas dissolves at one atmosphere, then three quantities will indeed dissolve at three atmospheres, reflecting the direct proportionality. This characteristic of Henry's Law is vital for divers using gas mixtures, as it informs safety measures regarding gas absorption and potential consequences of pressure changes underwater.

In contrast, Dalton's Law addresses the partial pressures of gas mixtures, Charles's Law deals with the relationship between gas volume and temperature, and Boyle's Law discusses the inverse relationship between pressure and volume. Each of these laws applies to different scenarios in gas behavior, but the specific context of the question is best explained by Henry's Law.