We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is Henry's Law?

By Karize Uy
Updated: May 21, 2024

In the science of chemistry, Henry’s law is a gas law stating that the mass of a dissolving gas within a certain amount of liquid is equally proportional to the pressure exerted on the gas. Simply put, the more pressure there is, the more gas can dissolve and blend into the liquid. Henry’s gas law also states that the gas’s solubility is inversely proportional to the temperature. If there is an increase in temperature, the gas’s solubility decreases.

The establishment of Henry’s law is attributed to William Henry, who in the 1800s, experimented with gases contained in water, using different temperatures and pressures. In formulaic terms, the gas law can be summed up this way: p = khc, where “p” represents the gas’s partial pressure, and the c is the solute’s concentration. The kh is the constant variable, depending on which gas is analyzed. The formula can also be expressed in other inverse forms, such as kh,pc = p/c or kh,cp = c/p.

The principle of Henry’s law is more easily understood when applied in everyday objects, such as in soft drinks, when the element of pressure is concerned. One can notice that a carbonated drink fizzes and forms bubbles when the bottle cap is removed and pressure is released, proof that the carbon gas is being released as well. If the bottle cap stays on, the pressure inside somehow forces and presses on to the carbon to dissolve in the sugared liquid, proving that a higher amount of pressure results in the gas being dissolved. This is why soft drinks do not taste as delicious when they are exposed in the air for too long, as much carbon has already been released.

Henry’s law can also be experienced by divers who usually feel heavier the more they descend into deeper waters. This is because the nitrogen is absorbed more by the bodily tissues because of the increased pressure underwater. When divers swim up, they experience a lighter feeling because of the release of gases, a very similar occurrence of the carbons fizzing out of the soda. Divers are advised, however, against ascending to the surface too quickly, as this can lead to decompression sickness, in which the gases are released all over the body and can cause severe pain, inflammation, and even seizures.

The element of temperature in Henry’s law can also be seen in soda drinks, or any gas-containing liquid, for the matter. As said before, the gas’s solubility decreases when the temperature increases, as observed when water is boiled and gas bubbles form on the surface. This also explains why experienced divers do not soak in a hot bath right after diving, because the hot water makes for a less soluble nitrogen that breaks away from the body, causing decompression sickness.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By Talentryto — On Jun 01, 2014

Anyone who is studying Henry's Law should also get some references on William Henry. He is an interesting person who did a lot for the field of science.

By Heavanet — On May 31, 2014

Henry's Law is one of those complicated science topics that is best understood by students when they experiment with it. A good way for a science teacher or parent to get their children interested in science is to do experiments with them that demonstrate this type of concept. Anyone interested can find a variety of experiments online for Henry's Law and just about any scientific concept that needs explaining.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.