Which Henry convention is used?

The page uses **p = k_H c** so **k_H** carries pressure/concentration units consistent with your chosen **p** (atm) and model **c**. Other texts define **H = p/x** or **c = k·p**; convert carefully between forms.

Why can real data disagree?

Salinity (Setschenow correction), pressure far from 1 atm, speciation (e.g. CO₂ ↔ H₂CO₃), and nonideality change activities; this model assumes an ideal dilute limit.

Is ΔH exactly the partial molar enthalpy of dissolution?

The exponential factor is a textbook-style temperature sensitivity knob; treat **ΔH** here as an illustrative parameter tied to the displayed slope **ΔH/R**, not a fitted spectroscopic value.

Henry's Law (Gas Solubility)

p = k_H c with k_H(T) from ΔH; c vs T at fixed p (ideal-dilute sketch).

Lower panel: ln k_H vs T — steeper |ΔH| bends the curve; slope vs 1/T is the van’t Hoff line.

Live graphs

About this model

Henry’s law states that, for a dilute solution in equilibrium with a gas headspace, the partial pressure of the solute gas is proportional to its concentration (or mole fraction) in the liquid: p = k_H c in one common linear form. The proportionality “constant” k_H is not truly constant: it varies with temperature because dissolution balances enthalpy and entropy. The simulator uses a compact van’t Hoff–type temperature dependence k_H(T) = k_ref exp((ΔH/R)(1/T − 1/T_ref)) anchored at 298.15 K, with ΔH interpreted as the dissolution enthalpy scale for the sketch. When ΔH < 0 (exothermic dissolution), k_H increases with T, so c = p/k_H decreases at fixed p — the familiar qualitative rule that cold solvent dissolves more gas. Presets give rough relative scales for O₂, N₂, and CO₂ in water-like sketches; they are pedagogical, not calibrated to NIST/CODATA Henry constants. The page also plots ln k_H versus T to visualize curvature from ΔH.

Who it's for: General chemistry (solubility of gases, oceans, carbonated drinks) and introductory chemical engineering mass transfer.

Key terms

Henry’s law
Henry constant
gas solubility
van’t Hoff equation
partial pressure
ideal dilute solution

How it works

Henry’s law in the linear dilute limit ties gas partial pressure p to equilibrium molarity c in the liquid: p = k_H c (textbook k_H has pressure/concentration units). k_H(T) is moved by dissolution enthalpy via a van’t Hoff–type temperature factor exp((ΔH/R)(1/T − 1/T_ref)) around a reference k_ref at 298.15 K; with ΔH < 0 (exothermic dissolution), k_H rises as T increases so c = p/k_H drops — “cold water holds more gas.” Numbers are order-of-magnitude sketches, not CODATA/NIST tables; activity coefficients and nonideality are omitted.

Key equations

p = k_H(T) · c ⇒ c = p / k_H(T)

k_H(T) = k_ref · exp((ΔH/R)(1/T − 1/T_ref))

Frequently asked questions

Which Henry convention is used?: The page uses p = k_H c so k_H carries pressure/concentration units consistent with your chosen p (atm) and model c. Other texts define H = p/x or c = k·p; convert carefully between forms.
Why can real data disagree?: Salinity (Setschenow correction), pressure far from 1 atm, speciation (e.g. CO₂ ↔ H₂CO₃), and nonideality change activities; this model assumes an ideal dilute limit.
Is ΔH exactly the partial molar enthalpy of dissolution?: The exponential factor is a textbook-style temperature sensitivity knob; treat ΔH here as an illustrative parameter tied to the displayed slope ΔH/R, not a fitted spectroscopic value.

Continue with similar topics in this category — or all 65 in Chemistry.

View category →

NewSchool

Le Châtelier Principle (Gas)

Launch Simulator

N₂ + 3H₂ ⇌ 2NH₃: T, V, add/remove species; Q vs K and relaxing mole bars.

NewSchool

Reaction Rate

Launch Simulator

Arrhenius k(T), order 0/1/2, [A](t) curves and particle tank.

NewSchool

Nernst Equation

Launch Simulator

E = E° − (RT/nF) ln Q: sliders for E°, n, T, and reaction quotient.

NewSchool

Gibbs Free Energy

Launch Simulator

ΔG = ΔH − TΔS; sign vs spontaneity at constant p,T (no Q or K).

NewSchool

Buffer Solution

Launch Simulator

Henderson–Hasselbalch vs strong acid: pH curve as H⁺ is added (mole model).

School

Titration Simulator

Launch Simulator

Add base to acid. pH curve in real time. Find equivalence point.

Henry's Law (Gas Solubility)

Live graphs

About this model

How it works

Key equations

Frequently asked questions

Related simulators

Le Châtelier Principle (Gas)

Reaction Rate

Nernst Equation

Gibbs Free Energy

Buffer Solution

Titration Simulator

Henry's Law (Gas Solubility)

Live graphs

About this model

How it works

Key equations

Frequently asked questions