Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

In order for a gas to escape from a solution, what condition must the solubility be?

1. High

2. Moderate

3. Low

4. None

The correct answer is: Low

For a gas to escape from a solution, the solubility of the gas must be low. When a gas is dissolved in a liquid, it exists in a dynamic equilibrium with the gas molecules in the gas phase above the solution. If the solubility of the gas is low, this indicates that there are fewer gas molecules interacting with the liquid. Therefore, when conditions change (such as a decrease in pressure or an increase in temperature), it becomes easier for the gas to overcome these interactions and transition from the liquid phase into the gaseous phase, allowing it to escape. High or moderate solubility would mean that the gas is more strongly held into the solution, making it less likely to escape until those conditions favoring the gas phase become significantly pronounced. Hence, a low solubility facilitates the escape of gas from the solution.