DOCSLIB.ORG

Changes of State

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Changes of State Changes of State It can be tricky to eat a popsicle outside on a hot day. In just a short time it will begin to melt. Slowly the solid popsicle becomes a liquid. As the popsicle melts, it goes through a change of state or phase change. A change of state when a substance changes physical form but not in molecule make up. The molecules do not change into something different they just gain or lose energy and movement. Ice, liquid water, and steam are all the same substance—water or H2O. The molecules of a substance move differently depending on the state of the substance. The molecules have different amounts of energy in each state of matter. So the main difference between a solid, liquid, and a gas how much the molecules are moving. 1. What is a change of state or phase? Solid to a Liquid One change of state happens when you add energy to the substance. This change of state is called melting. By adding energy to the molecules in a solid the molecules begin to move quicker and can break away from the other molecules. This happens slowly as each and every single molecule in the substance has to get enough energy to move quicker. Once the molecules have enough energy they begin to slide past the other molecules, and that is what makes a solid turn into a liquid. The temperature at which a substance goes from a solid to a liquid is it melting point. Ice melts into water at 32o F (0o C), whereas gold melts at 1,947.52 °F (1064.18 °C). That is quite a difference. A soft metal called gallium will melt in your hand because its melting point is 98 °F (30 °C), but the compound salt will not melt in your hand. It’s melting temperature is 1473 °F (801 °C). For a solid to melt, its molecules must overcome some of their attractions to each other. When a solid melts all of the energy goes into breaking the attractions that hold the molecules in place. Because you are adding energy melt is an endothermic change. 2. What is melting? 3. Adding energy or Taking away energy? Liquid to a Solid The change of state from a liquid to a solid is called freezing. Freezing is the reverse process to melting. For a liquid to freeze, the attraction between the particles must overcome the motion of the molecules sliding past each other. Think of it like a friend trying to grab your arm to hold you in place when you are stuck in the mob of students moving down the hallway. Your friend has to be stronger than the flow of traffic to hold you in place. When a liquid turns into a solid the molecules slow down and begin to vibrate in place. To cause freezing energy must be removed. Because you are removing heat to freeze a substance it is called a exothermic change. The point at which this happens is called the freezing point. Freezing points and melting point happen at the same temperature it just depends on whether you are adding or removing heat. 4. What is Freezing? 5. Adding energy or Taking away energy? 6. What is the difference between freezing point and melting points? Liquid to Gas If you’ve ever filled your bathroom full of steam you’ve experienced this next change of state called evaporation. Or how about that glass of cool aid you left out on the counter. You come back a few days later and it has less liquid in it than before….the liquid evaporated. Evaporation occurs at the surface of a liquid. You can see rapid evaporation in the form of boiling. The difference between boiling and evaporation is that boiling causes more of the molecules to move faster and thus they escape their attractions to each other quicker. Evaporation happens on the surface and is a much slower process. By adding energy you cause the molecules to move faster and break away from the others. The temperature that evaporation occurs is called the vaporization point or boiling point. Water boils at 212 °F (100 °C). 7. What is Evaporation? 8. Adding energy or Taking away energy? Gas to a Liquid The change of state from a Gas to a Liquid is called Condensation. If you’ve ever noticed that you mirror gets foggy in the bathroom or that the grass is wet on a spring morning even though it hasn’t rained, then you’ve seen condensation. For gas molecules to become a liquid the attraction for each other has to overcome the extreme movement of the molecules. Again think of the hallway example, but the crowd is moving much quicker. The point at which a substance goes through condensation is called its condensation point. For the quick moving molecules in a gas to slow down they have energy removed. Condensation is evaporation in reverse. 9. What is Condensation? 10. Adding energy or Taking away energy? Remember the molecules do not change chemically in a change of state, they only change in movement. 11‐14 Label each line on the diagram below with the name of the change of state..
Load more

Recommended publications
  • Equation of State for Benzene for Temperatures from the Melting Line up to 725 K with Pressures up to 500 Mpa†
    High Temperatures-High Pressures, Vol. 41, pp. 81–97 ©2012 Old City Publishing, Inc. Reprints available directly from the publisher Published by license under the OCP Science imprint, Photocopying permitted by license only a member of the Old City Publishing Group Equation of state for benzene for temperatures from the melting line up to 725 K with pressures up to 500 MPa† MONIKA THOL ,1,2,* ERIC W. Lemm ON 2 AND ROLAND SPAN 1 1Thermodynamics, Ruhr-University Bochum, Universitaetsstrasse 150, 44801 Bochum, Germany 2National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA Received: December 23, 2010. Accepted: April 17, 2011. An equation of state (EOS) is presented for the thermodynamic properties of benzene that is valid from the triple point temperature (278.674 K) to 725 K with pressures up to 500 MPa. The equation is expressed in terms of the Helmholtz energy as a function of temperature and density. This for- mulation can be used for the calculation of all thermodynamic properties. Comparisons to experimental data are given to establish the accuracy of the EOS. The approximate uncertainties (k = 2) of properties calculated with the new equation are 0.1% below T = 350 K and 0.2% above T = 350 K for vapor pressure and liquid density, 1% for saturated vapor density, 0.1% for density up to T = 350 K and p = 100 MPa, 0.1 – 0.5% in density above T = 350 K, 1% for the isobaric and saturated heat capaci- ties, and 0.5% in speed of sound. Deviations in the critical region are higher for all properties except vapor pressure.
    [Show full text]
  • Geometrical Vortex Lattice Pinning and Melting in Ybacuo Submicron Bridges Received: 10 August 2016 G
    www.nature.com/scientificreports OPEN Geometrical vortex lattice pinning and melting in YBaCuO submicron bridges Received: 10 August 2016 G. P. Papari1,*, A. Glatz2,3,*, F. Carillo4, D. Stornaiuolo1,5, D. Massarotti5,6, V. Rouco1, Accepted: 11 November 2016 L. Longobardi6,7, F. Beltram2, V. M. Vinokur2 & F. Tafuri5,6 Published: 23 December 2016 Since the discovery of high-temperature superconductors (HTSs), most efforts of researchers have been focused on the fabrication of superconducting devices capable of immobilizing vortices, hence of operating at enhanced temperatures and magnetic fields. Recent findings that geometric restrictions may induce self-arresting hypervortices recovering the dissipation-free state at high fields and temperatures made superconducting strips a mainstream of superconductivity studies. Here we report on the geometrical melting of the vortex lattice in a wide YBCO submicron bridge preceded by magnetoresistance (MR) oscillations fingerprinting the underlying regular vortex structure. Combined magnetoresistance measurements and numerical simulations unambiguously relate the resistance oscillations to the penetration of vortex rows with intermediate geometrical pinning and uncover the details of geometrical melting. Our findings offer a reliable and reproducible pathway for controlling vortices in geometrically restricted nanodevices and introduce a novel technique of geometrical spectroscopy, inferring detailed information of the structure of the vortex system through a combined use of MR curves and large-scale simulations. Superconductors are materials in which below the superconducting transition temperature, Tc, electrons form so-called Cooper pairs, which are bosons, hence occupying the same lowest quantum state1. The wave function of this Cooper condensate has a fixed phase. Hence, by virtue of the uncertainty principle, the number of Cooper pairs in the condensate is undefined.
    [Show full text]
  • Two-Dimensional Vortex Lattice Melting Superconducting Length
    Two-Dimensional Vortex Lattice Melting Superconducting Length-Scales and Vortex Lattices Flux Motion Melting Concepts Journal Paper Presentation: “Melting of the Vortex Lattice Through the Hexatic Phase in an MoGe3 Thin Film” 1 Repulsive Interaction Between Vortices Vortex Lattice 2 Vortex Melting in Superconducting Nb 3 (For 3D clean Type II superconductor) Vortex Lattice Expands on Freezing (Like Ice) Jump in the Magnetization 4 Melting Concepts 3D Solid Liquid Lindemann Criterion (∆r)2 ↵a 1st Order Transition ⇡ p 5 6 Journal Presentation Motivation/Context Results Interpretation Questions/Ideas for Future Work (aim for 30-45 mins) Please check the course site about the presentation schedule No class on The April 8, 15 Make-Ups on Ms April 12, 19 (Weekly Discussion to be Rescheduled) 7 First Definitive Observation of the Hexatic Phase in a Superconducting Film (with 8 thanks to Indranil Roy and Pratap Raychaudhuri) Two Dimensional Melting (BKT + HNY theory) 9 10 Hexatics have been observed in 2D colloidal systems Why not in the Melting of the Vortex Phase of Superconducting Films ?? 11 Quest for the Hexatic Liquid Phase in ↵ MoGe − Why Not Before ?? Orientational Coupling Hexatic Glass !! between Atomic and Vortex Lattices Solution: Amorphous Superconductor (no lattice effect) Very Weak Pinning BCS-Type Superconductor 12 Scanning Tunneling Spectroscopy (STS) Magnetotransport 13 14 15 16 17 The Resulting Phase Diagram 18 Summary First Observation of Hexatic Fluid Phase in a 2D Superconducting Film Pinning Significantly Weaker than in Previous Studies STS (imaging) Magnetotransport (“shear”) Questions/Ideas for the Future Size-Dependence of Hexatic Order Parameter ?? Low T limit of the Hexatic Fluid: Quantum Vortex Fluid ?? What happens in Layered Films ?? 19 20.
    [Show full text]
  • Guide to Understanding Condensation
    Guide to Understanding Condensation The complete Andersen® Owner-To-Owner™ limited warranty is available at: www.andersenwindows.com. “Andersen” is a registered trademark of Andersen Corporation. All other marks where denoted are marks of Andersen Corporation. © 2007 Andersen Corporation. All rights reserved. 7/07 INTRODUCTION 2 The moisture that suddenly appears in cold weather on the interior We have created this brochure to answer questions you may have or exterior of window and patio door glass can block the view, drip about condensation, indoor humidity and exterior condensation. on the floor or freeze on the glass. It can be an annoying problem. We’ll start with the basics and offer solutions and alternatives While it may seem natural to blame the windows or doors, interior along the way. condensation is really an indication of excess humidity in the home. Exterior condensation, on the other hand, is a form of dew — the Should you run into problems or situations not covered in the glass simply provides a surface on which the moisture can condense. following pages, please contact your Andersen retailer. The important thing to realize is that if excessive humidity is Visit the Andersen website: www.andersenwindows.com causing window condensation, it may also be causing problems elsewhere in your home. Here are some other signs of excess The Andersen customer service toll-free number: 1-888-888-7020. humidity: • A “damp feeling” in the home. • Staining or discoloration of interior surfaces. • Mold or mildew on surfaces or a “musty smell.” • Warped wooden surfaces. • Cracking, peeling or blistering interior or exterior paint.
    [Show full text]
  • Chapter 3 Bose-Einstein Condensation of an Ideal
    Chapter 3 Bose-Einstein Condensation of An Ideal Gas An ideal gas consisting of non-interacting Bose particles is a ¯ctitious system since every realistic Bose gas shows some level of particle-particle interaction. Nevertheless, such a mathematical model provides the simplest example for the realization of Bose-Einstein condensation. This simple model, ¯rst studied by A. Einstein [1], correctly describes important basic properties of actual non-ideal (interacting) Bose gas. In particular, such basic concepts as BEC critical temperature Tc (or critical particle density nc), condensate fraction N0=N and the dimensionality issue will be obtained. 3.1 The ideal Bose gas in the canonical and grand canonical ensemble Suppose an ideal gas of non-interacting particles with ¯xed particle number N is trapped in a box with a volume V and at equilibrium temperature T . We assume a particle system somehow establishes an equilibrium temperature in spite of the absence of interaction. Such a system can be characterized by the thermodynamic partition function of canonical ensemble X Z = e¡¯ER ; (3.1) R where R stands for a macroscopic state of the gas and is uniquely speci¯ed by the occupa- tion number ni of each single particle state i: fn0; n1; ¢ ¢ ¢ ¢ ¢ ¢g. ¯ = 1=kBT is a temperature parameter. Then, the total energy of a macroscopic state R is given by only the kinetic energy: X ER = "ini; (3.2) i where "i is the eigen-energy of the single particle state i and the occupation number ni satis¯es the normalization condition X N = ni: (3.3) i 1 The probability
    [Show full text]
  • Fish Technology Glossary
    Glossary of Fish Technology Terms A Selection of Terms Compiled by Kevin J. Whittle and Peter Howgate Prepared under contract to the Fisheries Industries Division of the Food and Agriculture Organization of the United Nations 6 December 2000 Last updated: February 2002 Kevin J. Whittle 1 GLOSSARY OF FISH TECHNOLOGY TERMS [Words highlighted in bold in the text of an entry refer to another entry. Words in parenthesis are alternatives.] Abnormalities Attributes of the fish that are not found in the great majority of that kind of fish. For example: atypical shapes; overall or patchy discolorations of skin or of fillet; diseased conditions; atypical odours or flavours. Generally, the term should be used for peculiarities present in the fish at the time of capture or harvesting, or developing very soon after; peculiarities arising during processing should be considered as defects. Acetic acid Formal chemical name, ethanoic acid. An organic acid of formula CH3.COOH. It is the main component, 3-6%, other than water, of vinegar. Used in fish technology in preparation of marinades. Acid curing See Marinating Actomyosin A combination of the two main proteins, actin and myosin, present in all muscle tissues. Additive A chemical added to a food to affect its properties. Objectives of including additives in a product include: increased stability during storage; inhibition of growth of microorganisms or production of microbial toxins; prevention or reduction of formation of off-flavours; improved sensory properties, particularly colours and appearance, affecting acceptability to the consumer; improved properties related to preparation and processing of food, for example, ability to create stable foams or emulsions, or to stabilise or thicken sauces.
    [Show full text]
  • Pressure Vs Temperature (Boiling Point)
    Boiling Points and Vapor Pressure Background Boiling Points and Vapor Pressure Background: Definitions Vapor Pressure: The equilibrium pressure of a vapor above its liquid; the pressure of the vapor resulting from the evaporation of a liquid above a sample of the liquid in a closed container. Boiling Point: The temperature at which the vapor pressure of a liquid is equal to the atmospheric (or applied) pressure. As the temperature of the liquid increases, the vapor pressure will increase, as seen below: https://www.chem.purdue.edu/gchelp/liquids/vpress.html Vapor pressure is interpreted in terms of molecules of liquid converting to the gaseous phase and escaping into the empty space above the liquid. In order for the molecules to escape, the intermolecular forces (Van der Waals, dipole- dipole, and hydrogen bonding) have to be overcome, which requires energy. This energy can come in the form of heat, aka increase in temperature. Due to this relationship between vapor pressure and temperature, the boiling point of a liquid decreases as the atmospheric pressure decreases since there is more room above the liquid for molecules to escape into at lower pressure. The graph below illustrates this relationship using common solvents and some terpenes: Pressure vs Temperature (boiling point) Ethanol Heptane Isopropyl Alcohol B-myrcene 290.0 B-caryophyllene d-Limonene Linalool Pulegone 270.0 250.0 1,8-cineole (eucalyptol) a-pinene a-terpineol terpineol-4-ol 230.0 p-cymene 210.0 190.0 170.0 150.0 130.0 110.0 90.0 Temperature (˚C) Temperature 70.0 50.0 30.0 10 20 30 40 50 60 70 80 90 100 200 300 400 500 600 760 10.0 -10.0 -30.0 Pressure (torr) 1 Boiling Points and Vapor Pressure Background As a very general rule of thumb, the boiling point of many liquids will drop about 0.5˚C for a 10mmHg decrease in pressure when operating in the region of 760 mmHg (atmospheric pressure).
    [Show full text]
  • Sodium Spinor Bose-Einstein Condensates
    SODIUM SPINOR BOSE-EINSTEIN CONDENSATES: ALL-OPTICAL PRODUCTION AND SPIN DYNAMICS By JIEJIANG BachelorofScienceinOpticalInformationScience UniversityofShanghaiforScienceandTechnology Shanghai,China 2009 SubmittedtotheFacultyofthe GraduateCollegeof OklahomaStateUniversity inpartialfulfillmentof therequirementsfor theDegreeof DOCTOROFPHILOSOPHY December,2015 COPYRIGHT c By JIE JIANG December, 2015 SODIUM SPINOR BOSE-EINSTEIN CONDENSATES: ALL-OPTICAL PRODUCTION AND SPIN DYNAMICS Dissertation Approved: Dr. Yingmei Liu Dissertation Advisor Dr. Albert T. Rosenberger Dr. Gil Summy Dr. Weili Zhang iii ACKNOWLEDGMENTS I would like to first express my sincere gratitude to my thesis advisor Dr. Yingmei Liu, who introduced ultracold quantum gases to me and guided me throughout my PhD study. I am greatly impressed by her profound knowledge, persistent enthusiasm and love in BEC research. It has been a truly rewarding and privilege experience to perform my PhD study under her guidance. I also want to thank my committee members, Dr. Albert Rosenberger, Dr. Gil Summy, and Dr. Weili Zhang for their advice and support during my PhD study. I thank Dr. Rosenberger for the knowledge in lasers and laser spectroscopy I learnt from him. I thank Dr. Summy for his support in the department and the academic exchange with his lab. Dr. Zhang offered me a unique opportunity to perform microfabrication in a cleanroom, which greatly extended my research experience. During my more than six years study at OSU, I had opportunities to work with many wonderful people and the team members in Liu’s lab have been providing endless help for me which is important to my work. Many thanks extend to my current colleagues Lichao Zhao, Tao Tang, Zihe Chen, and Micah Webb as well as our former members Zongkai Tian, Jared Austin, and Alex Behlen.
    [Show full text]
  • Δtb = M × Kb, Δtf = M × Kf
    8.1HW Colligative Properties.doc Colligative Properties of Solvents Use the Equations given in your notes to solve the Colligative Property Questions. ΔTb = m × Kb, ΔTf = m × Kf Freezing Boiling K K Solvent Formula Point f b Point (°C) (°C/m) (°C/m) (°C) Water H2O 0.000 100.000 1.858 0.521 Acetic acid HC2H3O2 16.60 118.5 3.59 3.08 Benzene C6H6 5.455 80.2 5.065 2.61 Camphor C10H16O 179.5 ... 40 ... Carbon disulfide CS2 ... 46.3 ... 2.40 Cyclohexane C6H12 6.55 80.74 20.0 2.79 Ethanol C2H5OH ... 78.3 ... 1.07 1. Which solvent’s freezing point is depressed the most by the addition of a solute? This is determined by the Freezing Point Depression constant, Kf. The substance with the highest value for Kf will be affected the most. This would be Camphor with a constant of 40. 2. Which solvent’s freezing point is depressed the least by the addition of a solute? By the same logic as above, the substance with the lowest value for Kf will be affected the least. This is water. Certainly the case could be made that Carbon disulfide and Ethanol are affected the least as they do not have a constant. 3. Which solvent’s boiling point is elevated the least by the addition of a solute? Water 4. Which solvent’s boiling point is elevated the most by the addition of a solute? Acetic Acid 5. How does Kf relate to Kb? Kf > Kb (fill in the blank) The freezing point constant is always greater.
    [Show full text]
  • It's Just a Phase!
    BASIS Lesson Plan Lesson Name: It’s Just a Phase! Grade Level Connection(s) NGSS Standards: Grade 2, Physical Science FOSS CA Edition: Grade 3 Physical Science: Matter and Energy Module *Note to teachers: Detailed standards connections can be found at the end of this lesson plan. Teaser/Overview Properties of matter are illustrated through a series of demonstrations and hands-on explorations. Students will learn to identify solids, liquids, and gases. Water will be used to demonstrate the three phases. Students will learn about sublimation through a fun experiment with dry ice (solid CO2). Next, they will compare the propensity of several liquids to evaporate. Finally, they will learn about freezing and melting while making ice cream. Lesson Objectives ● Students will be able to identify the three states of matter (solid, liquid, gas) based on the relative properties of those states. ● Students will understand how to describe the transition from one phase to another (melting, freezing, evaporation, condensation, sublimation) ● Students will learn that matter can change phase when heat/energy is added or removed Vocabulary Words ● Solid: A phase of matter that is characterized by a resistance to change in shape and volume. ● Liquid: A phase of matter that is characterized by a resistance to change in volume; a liquid takes the shape of its container ● Gas: A phase of matter that can change shape and volume ● Phase change: Transformation from one phase of matter to another ● Melting: Transformation from a solid to a liquid ● Freezing: Transformation
    [Show full text]
  • Melting of Lamellar Phases in Temperature Sensitive Colloid-Polymer Suspensions
    PHYSICAL REVIEW LETTERS week ending VOLUME 93, NUMBER 5 30 JULY 2004 Melting of Lamellar Phases in Temperature Sensitive Colloid-Polymer Suspensions A. M. Alsayed, Z. Dogic, and A. G. Yodh Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, USA (Received 10 March 2004; published 29 July 2004) We prepare a novel suspension composed of rodlike fd virus and thermosensitive polymer poly(N-isopropylacrylamide) whose phase diagram is temperature and concentration dependent. The system exhibits a rich variety of stable and metastable phases, and provides a unique opportunity to directly observe melting of lamellar phases and single lamellae. Typically, lamellar phases swell with increasing temperature before melting into the nematic phase. The highly swollen lamellae can be superheated as a result of topological nucleation barriers that slow the formation of the nematic phase. DOI: 10.1103/PhysRevLett.93.057801 PACS numbers: 64.70.Md, 61.30.–v, 64.60.My Melting of three-dimensional (3D) crystals is among lamellar phases and coexisting isotropic or nematic the most ubiquitous phase transitions in nature [1]. In phases. contrast to freezing, melting of 3D crystals usually has The fd=NIPA solutions are unusual new materials no associated energy barrier. Bulk melting is initiated at a whose lamellar phases differ from those of amphiphilic premelted surface, which then acts as a heterogeneous molecules. The lamellar phase can swell considerably and nucleation site and eliminates the nucleation barrier for melt into a nematic phase, a transition almost never the phase transition [2]. In this Letter, we investigate observed in block-copolymer lamellar systems.
    [Show full text]
  • Capillary Condensation of Colloid–Polymer Mixtures Confined
    INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER J. Phys.: Condens. Matter 15 (2003) S3411–S3420 PII: S0953-8984(03)66420-9 Capillary condensation of colloid–polymer mixtures confined between parallel plates Matthias Schmidt1,Andrea Fortini and Marjolein Dijkstra Soft Condensed Matter, Debye Institute, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands Received 21 July 2003 Published 20 November 2003 Onlineatstacks.iop.org/JPhysCM/15/S3411 Abstract We investigate the fluid–fluid demixing phase transition of the Asakura–Oosawa model colloid–polymer mixture confined between two smooth parallel hard walls using density functional theory and computer simulations. Comparing fluid density profiles for statepoints away from colloidal gas–liquid coexistence yields good agreement of the theoretical results with simulation data. Theoretical and simulation results predict consistently a shift of the demixing binodal and the critical point towards higher polymer reservoir packing fraction and towards higher colloid fugacities upon decreasing the plate separation distance. This implies capillary condensation of the colloid liquid phase, which should be experimentally observable inside slitlike micropores in contact with abulkcolloidal gas. 1. Introduction Capillary condensation denotes the phenomenon that spatial confinement can stabilize a liquid phase coexisting with its vapour in bulk [1, 2]. In order for this to happen the attractive interaction between the confining walls and the fluid particles needs to be sufficiently strong. Although the main body of work on this subject has been done in the context of confined simple liquids, one might expect that capillary condensation is particularly well suited to be studied with colloidal dispersions. In these complex fluids length scales are on the micron rather than on the ångstrom¨ scale which is typical for atomicsubstances.
    [Show full text]