Chapter 14: Gases
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THE SOLUBILITY of GASES in LIQUIDS Introductory Information C
THE SOLUBILITY OF GASES IN LIQUIDS Introductory Information C. L. Young, R. Battino, and H. L. Clever INTRODUCTION The Solubility Data Project aims to make a comprehensive search of the literature for data on the solubility of gases, liquids and solids in liquids. Data of suitable accuracy are compiled into data sheets set out in a uniform format. The data for each system are evaluated and where data of sufficient accuracy are available values are recommended and in some cases a smoothing equation is given to represent the variation of solubility with pressure and/or temperature. A text giving an evaluation and recommended values and the compiled data sheets are published on consecutive pages. The following paper by E. Wilhelm gives a rigorous thermodynamic treatment on the solubility of gases in liquids. DEFINITION OF GAS SOLUBILITY The distinction between vapor-liquid equilibria and the solubility of gases in liquids is arbitrary. It is generally accepted that the equilibrium set up at 300K between a typical gas such as argon and a liquid such as water is gas-liquid solubility whereas the equilibrium set up between hexane and cyclohexane at 350K is an example of vapor-liquid equilibrium. However, the distinction between gas-liquid solubility and vapor-liquid equilibrium is often not so clear. The equilibria set up between methane and propane above the critical temperature of methane and below the criti cal temperature of propane may be classed as vapor-liquid equilibrium or as gas-liquid solubility depending on the particular range of pressure considered and the particular worker concerned. -
AP Chemistry Chapter 5 Gases Ch
AP Chemistry Chapter 5 Gases Ch. 5 Gases Agenda 23 September 2017 Per 3 & 5 ○ 5.1 Pressure ○ 5.2 The Gas Laws ○ 5.3 The Ideal Gas Law ○ 5.4 Gas Stoichiometry ○ 5.5 Dalton’s Law of Partial Pressures ○ 5.6 The Kinetic Molecular Theory of Gases ○ 5.7 Effusion and Diffusion ○ 5.8 Real Gases ○ 5.9 Characteristics of Several Real Gases ○ 5.10 Chemistry in the Atmosphere 5.1 Units of Pressure 760 mm Hg = 760 Torr = 1 atm Pressure = Force = Newton = pascal (Pa) Area m2 5.2 Gas Laws of Boyle, Charles and Avogadro PV = k Slope = k V = k P y = k(1/P) + 0 5.2 Gas Laws of Boyle - use the actual data from Boyle’s Experiment Table 5.1 And Desmos to plot Volume vs. Pressure And then Pressure vs 1/V. And PV vs. V And PV vs. P Boyle’s Law 3 centuries later? Boyle’s law only holds precisely at very low pressures.Measurements at higher pressures reveal PV is not constant, but varies as pressure varies. Deviations slight at pressures close to 1 atm we assume gases obey Boyle’s law in our calcs. A gas that strictly obeys Boyle’s Law is called an Ideal gas. Extrapolate (extend the line beyond the experimental points) back to zero pressure to find “ideal” value for k, 22.41 L atm Look Extrapolatefamiliar? (extend the line beyond the experimental points) back to zero pressure to find “ideal” value for k, 22.41 L atm The volume of a gas at constant pressure increases linearly with the Charles’ Law temperature of the gas. -
THE SOLUBILITY of GASES in LIQUIDS INTRODUCTION the Solubility Data Project Aims to Make a Comprehensive Search of the Lit- Erat
THE SOLUBILITY OF GASES IN LIQUIDS R. Battino, H. L. Clever and C. L. Young INTRODUCTION The Solubility Data Project aims to make a comprehensive search of the lit erature for data on the solubility of gases, liquids and solids in liquids. Data of suitable accuracy are compiled into data sheets set out in a uni form format. The data for each system are evaluated and where data of suf ficient accuracy are available values recommended and in some cases a smoothing equation suggested to represent the variation of solubility with pressure and/or temperature. A text giving an evaluation and recommended values and the compiled data sheets are pUblished on consecutive pages. DEFINITION OF GAS SOLUBILITY The distinction between vapor-liquid equilibria and the solUbility of gases in liquids is arbitrary. It is generally accepted that the equilibrium set up at 300K between a typical gas such as argon and a liquid such as water is gas liquid solubility whereas the equilibrium set up between hexane and cyclohexane at 350K is an example of vapor-liquid equilibrium. However, the distinction between gas-liquid solUbility and vapor-liquid equilibrium is often not so clear. The equilibria set up between methane and propane above the critical temperature of methane and below the critical temperature of propane may be classed as vapor-liquid equilibrium or as gas-liquid solu bility depending on the particular range of pressure considered and the par ticular worker concerned. The difficulty partly stems from our inability to rigorously distinguish between a gas, a vapor, and a liquid, which has been discussed in numerous textbooks. -
CEE 370 Environmental Engineering Principles Henry's
CEE 370 Lecture #7 9/18/2019 Updated: 18 September 2019 Print version CEE 370 Environmental Engineering Principles Lecture #7 Environmental Chemistry V: Thermodynamics, Henry’s Law, Acids-bases II Reading: Mihelcic & Zimmerman, Chapter 3 Davis & Masten, Chapter 2 Mihelcic, Chapt 3 David Reckhow CEE 370 L#7 1 Henry’s Law Henry's Law states that the amount of a gas that dissolves into a liquid is proportional to the partial pressure that gas exerts on the surface of the liquid. In equation form, that is: C AH = K p A where, CA = concentration of A, [mol/L] or [mg/L] KH = equilibrium constant (often called Henry's Law constant), [mol/L-atm] or [mg/L-atm] pA = partial pressure of A, [atm] David Reckhow CEE 370 L#7 2 Lecture #7 Dave Reckhow 1 CEE 370 Lecture #7 9/18/2019 Henry’s Law Constants Reaction Name Kh, mol/L-atm pKh = -log Kh -2 CO2(g) _ CO2(aq) Carbon 3.41 x 10 1.47 dioxide NH3(g) _ NH3(aq) Ammonia 57.6 -1.76 -1 H2S(g) _ H2S(aq) Hydrogen 1.02 x 10 0.99 sulfide -3 CH4(g) _ CH4(aq) Methane 1.50 x 10 2.82 -3 O2(g) _ O2(aq) Oxygen 1.26 x 10 2.90 David Reckhow CEE 370 L#7 3 Example: Solubility of O2 in Water Background Although the atmosphere we breathe is comprised of approximately 20.9 percent oxygen, oxygen is only slightly soluble in water. In addition, the solubility decreases as the temperature increases. -
Ideal Gasses Is Known As the Ideal Gas Law
ESCI 341 – Atmospheric Thermodynamics Lesson 4 –Ideal Gases References: An Introduction to Atmospheric Thermodynamics, Tsonis Introduction to Theoretical Meteorology, Hess Physical Chemistry (4th edition), Levine Thermodynamics and an Introduction to Thermostatistics, Callen IDEAL GASES An ideal gas is a gas with the following properties: There are no intermolecular forces, except during collisions. All collisions are elastic. The individual gas molecules have no volume (they behave like point masses). The equation of state for ideal gasses is known as the ideal gas law. The ideal gas law was discovered empirically, but can also be derived theoretically. The form we are most familiar with, pV nRT . Ideal Gas Law (1) R has a value of 8.3145 J-mol1-K1, and n is the number of moles (not molecules). A true ideal gas would be monatomic, meaning each molecule is comprised of a single atom. Real gasses in the atmosphere, such as O2 and N2, are diatomic, and some gasses such as CO2 and O3 are triatomic. Real atmospheric gasses have rotational and vibrational kinetic energy, in addition to translational kinetic energy. Even though the gasses that make up the atmosphere aren’t monatomic, they still closely obey the ideal gas law at the pressures and temperatures encountered in the atmosphere, so we can still use the ideal gas law. FORM OF IDEAL GAS LAW MOST USED BY METEOROLOGISTS In meteorology we use a modified form of the ideal gas law. We first divide (1) by volume to get n p RT . V we then multiply the RHS top and bottom by the molecular weight of the gas, M, to get Mn R p T . -
Unit 5 Interactive Notebook Gas Laws and Kinetic Molecular Theory Grant Union High School January 6, 2014 – January 29, 2014
Unit 5 Interactive Notebook Gas Laws and Kinetic Molecular Theory Grant Union High School January 6, 2014 – January 29, 2014 Student Mastery Scale of Learning Goals Date Page Std Learning Goal Homework Mastery 1/6/14 1/7/14 1/8/14 1/9/14 1/10/14 1/13/14 1/14/14 1/15/14 1 1/16/14 1/21/14 1/22/14 1/23/14 1/24/14 1/27/14 1/28/14 1/29/14 Unit 5 EXAM 2 California Standard Gas Laws 4. The kinetic molecular theory describes the motion of atoms and molecules and explains the properties of gases. As a basis for understanding this concept: a. Students know the random motion of molecules and their collisions with a surface create the observable pressure on that surface. Fluids, gases or liquids, consist of molecules that freely move past each other in random directions. Intermolecular forces hold the atoms or molecules in liquids close to each other. Gases consist of tiny particles, either atoms or molecules, spaced far apart from each other and free to move at high speeds. Pressure is defined as force per unit area. The force in fluids comes from collisions of atoms or molecules with the walls of a container. Air pressure is created by the weight of the gas in the atmosphere striking surfaces. Gravity pulls air molecules toward Earth, the surface that they strike. Water pressure can be understood in the same fashion, but the pressures are much greater because of the greater density of water. -
Masteringphysics: Assignmen
MasteringPhysics: Assignment Print View http://session.masteringphysics.com/myct/assignmentPrint... Manage this Assignment: Chapter 18 Due: 12:00am on Saturday, July 3, 2010 Note: You will receive no credit for late submissions. To learn more, read your instructor's Grading Policy A Law for Scuba Divers Description: Find the increase in the concentration of air in a scuba diver's lungs. Find the number of moles of air exhaled. Also, consider the isothermal expansion of air as a freediver diver surfaces. Identify the proper pV graph. Associated medical conditions discussed. SCUBA is an acronym for self-contained underwater breathing apparatus. Scuba diving has become an increasingly popular sport, but it requires training and certification owing to its many dangers. In this problem you will explore the biophysics that underlies the two main conditions that may result from diving in an incorrect or unsafe manner. While underwater, a scuba diver must breathe compressed air to compensate for the increased underwater pressure. There are a couple of reasons for this: 1. If the air were not at the same pressure as the water, the pipe carrying the air might close off or collapse under the external water pressure. 2. Compressed air is also more concentrated than the air we normally breathe, so the diver can afford to breathe more shallowly and less often. A mechanical device called a regulator dispenses air at the proper (higher than atmospheric) pressure so that the diver can inhale. Part A Suppose Gabor, a scuba diver, is at a depth of . Assume that: 1. The air pressure in his air tract is the same as the net water pressure at this depth. -
GAS LAWS OVERVIEW Created By: Julio Cesar Torres Orozco
GAS LAWS OVERVIEW Created by: Julio Cesar Torres Orozco Background: The gas laws we will be discussing in this handout were created over four centuries ago, and have been helpful for scientist to find pressures, amounts, volumes and temperatures of gases under different conditions, and the relationship there exists between these variables. The fundamental gas laws are the following: Boyle’s Law, Charles’ Law, and Avogadro’s Law. We will also discuss the Gay-Lussac law When we combine these Laws, we get the Combined Gas Law and the Ideal Gas Law. GAS LAWS: ! Boyle’s Law: In 1662, Robert Boyle discovered the relationship between pressure and volume, assuming constant temperature and amount of gas. If the temperature remains constant, as the volume of a container increases, the pressure the gas will exert will decrease. Therefore: RELATIONSHIP: Pressure is inversely proportional to volume EQUATION: P1 x V1 = P2 x V2 GRAPHIC REPRESENTATION: GAS LAWS OVERVIEW Created by: Julio Cesar Torres Orozco ! Charles’ Law: In 1787, Jacques Charles discovered how temperature and volume are related, assuming that the amount of gas and pressure are constant. An increase in temperature will also increase the volume of the gas. Therefore: RELATIONSHIP: Volume is directly proportional to temperature EQUATION: GRAPHIC REPRESENTATION: ! Gay-Lussacs’ Law: This law shows the relationship there exists between temperature and pressure of gasses. Given a constant volume, if the temperature increases, the pressure will also increase. Therefore: RELATIONSHIP: Pressure is directly proportional to temperature EQUATION: GAS LAWS OVERVIEW Created by: Julio Cesar Torres Orozco GRAPHIC REPRESENTATION: ! Avogadro’s Law: In 1811, Amedeo Avogadro was able to identify the correlation between the amount of gas (n) and its volume, assuming that temperature and pressure are constant. -
The Gas Laws A. Introduction. 1. Comparison of Three States of Matter
CHAPTER FIVE: THE GASEOUS STATE Part One: The Gas Laws A. Introduction. 1. Comparison of three states of matter: solids condensed states liquids (high density, hard to compress) fluids (flow freely) gases (low density, easy to compress) 1 mole liquid H2O occupies 18 mL 1 mole H2O vapor at 100° C and atmospheric pressure occupies 30,600mL Thus, gas molecules must be far apart compared to molecular sizes and interact only weakly. 2. Composition of dry air by volume: 78% N2, 21% O2, 1% Ar, traces of other. 3. Properties of gases: a. Easily compressed into small volumes by applying pressure. b. Exert a pressure P on their surroundings; an equal pressure must be applied to confine them. c. Expand without limit to uniformly and completely occupy the volume of any container. d. Individual molecules exhibit a chaotic motion called diffusion. e. Properties described by gas laws. Show them “A Little Box of Air.” Chapter 5 Page 1 B. Pressure (P). (Section 5.1) 1. P = force per unit area produced by incessant collisions of particles with container walls. 2. Measurement of atmospheric pressure (Torricelli barometer): h ∝ pressure average height h: = 760 mm Hg at sea level P = 760 mm Hg = 1 atmosphere (atm) ≈ 30 inches 1 mm Hg = 1 “torr” SI unit of P is the pascal (Pa) 760 mm Hg: = 1 atm = 1.01325 x 105 Pa = 101.325kPa 3. Pressure of a column of liquid = hydrostatic pressure: P = gdh = accel. of gravity x density of liquid x height of column 2 g=9.81 m/s Chapter 5 Page 2 4. -
Gases Boyles Law Amontons Law Charles Law ∴ Combined Gas
Gas Physics FICK’S LAW Adolf Fick, 1858 Properties of “Ideal” Gases Fick’s law of diffusion of a gas across a fluid membrane: • Gases are composed of molecules whose size is negligible compared to the average distance between them. Rate of diffusion = KA(P2–P1)/D – Gas has a low density because its molecules are spread apart over a large volume. • Molecules move in random lines in all directions and at various speeds. Wherein: – The forces of attraction or repulsion between two molecules in a gas are very weak or negligible, except when they collide. K = a temperature-dependent diffusion constant. – When molecules collide with one another, no kinetic energy is lost. A = the surface area available for diffusion. • The average kinetic energy of a molecule is proportional to the absolute temperature. (P2–P1) = The difference in concentraon (paral • Gases are easily expandable and compressible (unlike solids and liquids). pressure) of the gas across the membrane. • A gas will completely fill whatever container it is in. D = the distance over which diffusion must take place. – i.e., container volume = gas volume • Gases have a measurement of pressure (force exerted per unit area of surface). – Units: 1 atmosphere [atm] (≈ 1 bar) = 760 mmHg (= 760 torr) = 14.7 psi = 0.1 MPa Boyles Law Amontons Law • Gas pressure (P) is inversely proportional to gas volume (V) • Gas pressure (P) is directly proportional to absolute gas • P ∝ 1/V temperature (T in °K) ∴ ↑V→↓P ↑P→↓V ↓V →↑P ↓P →↑V • 0°C = 273°K • P ∝ T • ∴ P V =P V (if no gas is added/lost and temperature -
The Behavior and Applications of Gases
329670_ch10.qxd 07/20/2006 11:32 AM Page 394 The Behavior and Applications Contents and Selected Applications 10.1 The Nature of Gases of Gases 10.2 Production of Hydrogen and the Meaning of Pressure 10.3 Mixtures of Gases—Dalton’s Law and Food Packaging Chemical Encounters: Dalton’s Law and Food Packaging 10.4 The Gas Laws—Relating the Behavior of Gases to Key Properties Chemical Encounters: Balloons and Ozone Analysis 10.5 The Ideal Gas Equation 10.6 Applications of the Ideal Gas Equation Earth’s atmosphere is a very thin layer of gases (only 560 km thick) that surrounds Chemical Encounters: Automobile Air Bags Chemical Encounters: Acetylene the planet. Although the atmosphere makes up only a small part of our planet, 10.7 Kinetic-Molecular Theory it is vital to our survival. 10.8 Effusion and Diffusion 10.9 Industrialization: A Wonderful, Yet Cautionary, Tale Chemical Encounters: Ozone Chemical Encounters: The Greenhouse Effect 394 329670_ch10.qxd 6/19/06 1:45 PM Page 395 Our planet is surrounded by a relatively thin layer known as an atmosphere. It supplies all living organisms on Earth with breathable air, serves as the vehicle to deliver rain to our crops, and protects us from harmful ultraviolet rays from the Sun. Although it does contain solid particles, such as dust and smoke, and liquid droplets, such as sea TABLE 10.1 Composition of Dry Air spray and clouds, much of the atmosphere we live in is Percent Parts per Million actually a mixture of the gases shown in Table 10.1. -
The Ideal and Combined Gas Laws PV = Nrt Or P1V1 = P2V2 T1 T2
The Ideal and Combined Gas Laws PV = nRT or P1V1 = P2V2 T1 T2 Use your knowledge of the ideal and combined gas laws to solve the following problems. If it involves moles or grams, it must be PV = nRT 1) If four moles of a gas at a pressure of 5.4 atmospheres have a volume of 120 liters, what is the temperature? 2) If I initially have a gas with a pressure of 84 kPa and a temperature of 350 C and I heat it an additional 230 degrees, what will the new pressure be? Assume the volume of the container is constant. 3) My car has an internal volume of 2600 liters. If the sun heats my car from a temperature of 200 C to a temperature of 550 C, what will the pressure inside my car be? Assume the pressure was initially 760 mm Hg. 4) How many moles of gas are in my car in problem #3? 5) A toy balloon filled with air has an internal pressure of 1.25 atm and a volume of 2.50 L. If I take the balloon to the bottom of the ocean where the pressure is 95 atmospheres, what will the new volume of the balloon be? How many moles of gas does the balloon hold? (Assume T = 285 K) For chemistry help, visit www.chemfiesta.com © 2000 Cavalcade Publishing - All Rights Reserved MIXED GAS LAWS WORKSHEET Created by Tara L. Moore at www.learning.mgccc.cc.ms.us/pk/sciencedocs/gaslawwksheet.htm Directions: Answer each question below.