Canonical Question

Gas and Liquid Laws

Historical V4 W.i 1 appearance

Master answer

Dalton’s Law (of partial pressures)

\[P_{total}\;=\;P_{1}\;+\;P_{2}\;+\;P_{3}\;+\;.\;.\;.\;+P_{n}\;\equiv\;\sum_{i=1}^{n}\;P_{i}\]

The total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases.

Boyle’s Law

\[P\;\propto\;{1\over V}\]

The pressure exerted by a gas is inversly proportional to the volume it occupies, assuming the amount of gas and the temperature is constant

Henry’s Law

\[p\;=\;k_{H}\;c\]

where c=solubility of a gas at a fixed temp, k=Henry’s Law (equilibrium) constant p = partial pressure of the gas

Given a constant temperature, the amount of gas dissolved in a liquid, is proportional to the partial pressure of that gas

Graham’s Law

\[Diffusion\;\propto\;{1 \over \sqrt{MW}}\]

The rate of diffusion of a molecule is inversely proportional to the square root of its molecular weight

Fick’s Law of Diffusion

\[Diffusion \propto \;Diffusion\;Coefficient\;\:{(Concentration\;gradient\;×\;Surface\;area) \over Thickness}\]

Diffusive flux goes from a high-concentration area to a low-concentration area proportional to both the concentration gradient and surface area and is inversely proportional to the thickness of the membrane.

JC / Sakurai 2016

Answer by JC, Sakurai

Exam appearances

Exam	Exact wording	Relationship	Success
2013B Q12	Explain the following laws: a. Dalton’s b. Boyle’s c. Henry’s d. Graham’s e. Fick’s Law of Diffusion	historical_member	—