Certified Hyperbaric Technologist Practice Test

Which scenario is a common illustration of Henry's Law?

1. An open bottle of water

2. A sealed bottle of soda

3. A boiling kettle

4. A closed container of oil

The correct answer is: A sealed bottle of soda

Henry's Law states that the amount of gas that dissolves in a liquid is directly proportional to the partial pressure of that gas above the liquid, provided that the temperature remains constant. In the context of your question, a sealed bottle of soda is a prime example of this principle. When the soda is sealed, carbon dioxide gas is present in the headspace above the liquid. Due to the pressure from the sealed cap, a higher concentration of carbon dioxide is maintained in the liquid, leading to its dissolution. When the bottle is opened, the pressure above the liquid decreases, and the carbon dioxide begins to escape, illustrating Henry's Law through the relationship between gas pressure and solubility. The other scenarios do not effectively demonstrate this concept. An open bottle of water does not have any additional pressure from gas above it, and while boiling water involves gas bubbles forming, it is not related to gas solubility in the same way. Similarly, a closed container of oil does not involve a gas that is soluble in the oil, making it less relevant to Henry's Law.