4: Gases
- Page ID
- 498391
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- 4.0: Introduction
- Water from Air: A Chemistry Breakthrough for Clean Drinking Water
- 4.1: States of Matter
- Matter exists in three states: gas, liquid, and solid. Gas particles are far apart, making gases highly compressible. Gases expand to fill their container. Liquid particles are close together, making liquids dense and relatively incompressible, but they can move past each other, allowing liquids to take the shape of their container. The particles of solids are close together and vibrate in fixed positions, making solids dense, rigid, and incompressible. The physical state of a substance depen
- 4.2: Pressure
- Pressure is defined as force per unit area, with the SI unit being the pascal (Pa), where 1 Pa = 1 N/m². Atmospheric pressure is commonly measured using a barometer, a closed, inverted mercury-filled tube, where the height of the mercury column corresponds to atmospheric pressure. A manometer is used to measure the pressure of a gas sample. A closed-end manometer directly measures gas pressure relative to a vacuum, while an open-end manometer compares gas pressure to atmospheric pressure.
- 4.3: Relating Pressure, Volume, Amount, and Temperature - The Ideal Gas Law
- The behaviour of gases follows several fundamental laws based on experimental observations of their temperature, volume, pressure, and amount in moles. The equations describing these laws are special cases of the ideal gas law, PV = nRT, where P is the pressure of the gas, V is the volume, n is the number of moles of the gas, T is the temperature in K, and R is the universal gas constant.
- 4.4: Further Applications of the Ideal-Gas Equation
- The ideal gas law can be used to determine the density and molar mass of gases. The stoichiometric relationships between reactants and products can be expressed in terms of moles, masses, solution volumes, or gas volumes. The ideal gas law allows us to calculate the quantities of gaseous reactants and products involved in a chemical reaction.
- 4.5: Gas Mixtures and Partial Pressures
- The pressure exerted by an individual gas in a mixture is known as its partial pressure and is directly proportional to its mole fraction. The partial pressure of each gas is independent of other gases in the mixture. The total pressure of a gas mixture is the sum of the partial pressures of all its components. The mole fraction is the ratio of the number of moles of a specific gas to the total number of moles of all gases present.
- 4.6: The Kinetic-Molecular Theory
- The kinetic molecular theory is a simple yet effective model that explains ideal gas behavior. It assumes that gases consist of widely separated particles with negligible volume, moving constantly and colliding elastically with each other and the container walls. The average kinetic energy of gas particles is determined by temperature. Gas particles exhibit a range of velocities, with the distribution depending on both temperature and particle mass.
- 4.E: Gases (Exercises)
- Apply what you’ve learned about gases and check your understanding. These problems will help you build confidence with key concepts such as the ideal gas law, partial pressures, and gas stoichiometry. You will use these skills throughout the course, so give them a try!
Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at http://cnx.org/contents/85abf193-2bd...a7ac8df6@9.110).
- Thumbnail: As long as black-body radiation (not shown) doesn't escape a system, atoms in thermal agitation undergo essentially elastic collisions. On average, two atoms rebound from each other with the same kinetic energy as before a collision. Five atoms are colored red so their paths of motion are easier to see. (Public Domain; Greg L via Wikipedia)