The Properties of Water
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Chapter 5 Measures of Humidity Phases of Water
Chapter 5 Atmospheric Moisture Measures of Humidity 1. Absolute humidity 2. Specific humidity 3. Actual vapor pressure 4. Saturation vapor pressure 5. Relative humidity 6. Dew point Phases of Water Water Vapor n o su ti b ra li o n m p io d a a at ep t v s o io e en s n d it n io o n c freezing Liquid Water Ice melting 1 Coexistence of Water & Vapor • Even below the boiling point, some water molecules leave the liquid (evaporation). • Similarly, some water molecules from the air enter the liquid (condense). • The behavior happens over ice too (sublimation and condensation). Saturation • If we cap the air over the water, then more and more water molecules will enter the air until saturation is reached. • At saturation there is a balance between the number of water molecules leaving the liquid and entering it. • Saturation can occur over ice too. Hydrologic Cycle 2 Air Parcel • Enclose a volume of air in an imaginary thin elastic container, which we will call an air parcel. • It contains oxygen, nitrogen, water vapor, and other molecules in the air. 1. Absolute Humidity Mass of water vapor Absolute humidity = Volume of air The absolute humidity changes with the volume of the parcel, which can change with temperature or pressure. 2. Specific Humidity Mass of water vapor Specific humidity = Total mass of air The specific humidity does not change with parcel volume. 3 Specific Humidity vs. Latitude • The highest specific humidities are observed in the tropics and the lowest values in the polar regions. -
Insar Water Vapor Data Assimilation Into Mesoscale Model
This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 1 InSAR Water Vapor Data Assimilation into Mesoscale Model MM5: Technique and Pilot Study Emanuela Pichelli, Rossella Ferretti, Domenico Cimini, Giulia Panegrossi, Daniele Perissin, Nazzareno Pierdicca, Senior Member, IEEE, Fabio Rocca, and Bjorn Rommen Abstract—In this study, a technique developed to retrieve inte- an extremely important element of the atmosphere because its grated water vapor from interferometric synthetic aperture radar distribution is related to clouds, precipitation formation, and it (InSAR) data is described, and a three-dimensional variational represents a large proportion of the energy budget in the atmo- assimilation experiment of the retrieved precipitable water vapor into the mesoscale weather prediction model MM5 is carried out. sphere. Its representation inside numerical weather prediction The InSAR measurements were available in the framework of the (NWP) models is critical to improve the weather forecast. It is European Space Agency (ESA) project for the “Mitigation of elec- also very challenging because water vapor is involved in pro- tromagnetic transmission errors induced by atmospheric water cesses over a wide range of spatial and temporal scales. An vapor effects” (METAWAVE), whose goal was to analyze and pos- improvement in atmospheric water vapor monitoring that can sibly predict the phase delay induced by atmospheric water vapor on the spaceborne radar signal. The impact of the assimilation on be assimilated in NWP models would improve the forecast the model forecast is investigated in terms of temperature, water accuracy of precipitation and severe weather [1], [3]. -
Exploring Density
Exploring Density Students investigate the densities of different liquids and solids and understand how density may help identify a substance. Suggested Grade Range: 6-8 Approximate Time: 1 hour Relevant National Content Standards: Next Generation Science Standards Science and Engineering Practices: Developing and using Models Modeling in 6–8 builds on K–5 experiences and progresses to developing, using, and revising models to describe, test, and predict more abstract phenomena and design systems. • Develop and use a model to describe phenomena. Science and Engineering Practices: Analyzing and Interpreting Data Analyzing data in 6-8 builds on K-5 and progresses to extending quantitative analysis to investigations, distinguishing between correlation and causation, and basic statistical techniques of data and error analysis. • Analyze and interpret data to determine similarities and differences in findings. Disciplinary Core Ideas: PS1.A Structure and Properties of Matter Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it. Common Core State Standard: 7NS 2. Apply and extend previous understanding of multiplication and division and of fractions to multiply and divide rational numbers. 3. Solve real-world and mathematical problems involving the four operations with rational numbers. Common Core State Standard: 7EE Solve real-life and mathematical problems using numerical and algebraic expressions and equations. 4. Use variables to represent -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere. -
Glossary of Terms
GLOSSARY OF TERMS For the purpose of this Handbook, the following definitions and abbreviations shall apply. Although all of the definitions and abbreviations listed below may have not been used in this Handbook, the additional terminology is provided to assist the user of Handbook in understanding technical terminology associated with Drainage Improvement Projects and the associated regulations. Program-specific terms have been defined separately for each program and are contained in pertinent sub-sections of Section 2 of this handbook. ACRONYMS ASTM American Society for Testing Materials CBBEL Christopher B. Burke Engineering, Ltd. COE United States Army Corps of Engineers EPA Environmental Protection Agency IDEM Indiana Department of Environmental Management IDNR Indiana Department of Natural Resources NRCS USDA-Natural Resources Conservation Service SWCD Soil and Water Conservation District USDA United States Department of Agriculture USFWS United States Fish and Wildlife Service DEFINITIONS AASHTO Classification. The official classification of soil materials and soil aggregate mixtures for highway construction used by the American Association of State Highway and Transportation Officials. Abutment. The sloping sides of a valley that supports the ends of a dam. Acre-Foot. The volume of water that will cover 1 acre to a depth of 1 ft. Aggregate. (1) The sand and gravel portion of concrete (65 to 75% by volume), the rest being cement and water. Fine aggregate contains particles ranging from 1/4 in. down to that retained on a 200-mesh screen. Coarse aggregate ranges from 1/4 in. up to l½ in. (2) That which is installed for the purpose of changing drainage characteristics. -
Carbon Dioxide
Safetygram 18 Carbon dioxide Carbon dioxide is nonflammable, colorless, and odorless in the gaseous and liquid states. Carbon dioxide is a minor but important constituent of the atmosphere, averaging about 0.036% or 360 ppm by volume. It is also a normal end-prod- uct of human and animal metabolism. Dry carbon dioxide is a relatively inert gas. In the event moisture is present in high concentrations, carbonic acid may be formed and materials resistant to this acid should be used. High flow rates or rapid depressurization of a system can cause temperatures approaching the sublimation point (–109.3°F [–78.5°C]) to be attained within the system. Carbon dioxide will convert directly from a liquid to a solid if the liquid is depressurized below 76 psia (61 psig). The use of ma- terials which become brittle at low temperatures should be avoided in applications where temperatures less than –20°F (–29°C) are expected. Vessels and piping used in carbon dioxide service should be designed to the American Society of Mechanical Engineers (ASME) or Department of Transportation (DOT) codes for the pressures and temperatures involved. Physical properties are listed in Table 1. Carbon dioxide in the gaseous state is colorless and odorless and not easily detectable. Gaseous carbon dioxide is 1.5 times denser than air and therefore is found in greater concentrations at low levels. Ventilation systems should be designed to exhaust from the lowest levels and allow make-up air to enter at a higher level. Manufacture Carbon dioxide is produced as a crude by-product of a number of manufactur- ing processes. -
Guidelines for the Use of Atomic Weights 5 10 11 12 DOI: ..., Received ...; Accepted
IUPAC Guidelines for the us e of atomic weights For Peer Review Only Journal: Pure and Applied Chemistry Manuscript ID PAC-REC-16-04-01 Manuscript Type: Recommendation Date Submitted by the Author: 01-Apr-2016 Complete List of Authors: van der Veen, Adriaan; VSL Meija, Juris Possolo, Antonio; National Institute of Standards and Technology Hibbert, David; University of New South Wales, School of Chemistry atomic weights, atomic-weight intervals, molecular weight, standard Keywords: atomic weight, measurement uncertainty, uncertainty propagation Author-Supplied Keywords: P.O. 13757, Research Triangle Park, NC (919) 485-8700 Page 1 of 13 IUPAC Pure Appl. Chem. 2016; aop 1 2 3 4 Sponsoring body: IUPAC Inorganic Chemistry Division Committee: see more details on page XXX. 5 IUPAC Recommendation 6 7 Adriaan M. H. van der Veen*, Juris Meija, Antonio Possolo, and D. Brynn Hibbert 8 9 Guidelines for the use of atomic weights 5 10 11 12 DOI: ..., Received ...; accepted ... 13 14 Abstract: Standard atomicFor weights Peer are widely used Review in science, yet the uncertainties Only associated with these 15 values are not well-understood. This recommendation provides guidance on the use of standard atomic 16 weights and their uncertainties. Furthermore, methods are provided for calculating standard uncertainties 17 of molecular weights of substances. Methods are also outlined to compute material-specific atomic weights 10 18 whose associated uncertainty may be smaller than the uncertainty associated with the standard atomic 19 weights. 20 21 Keywords: atomic weights; atomic-weight intervals; molecular weight; standard atomic weight; uncertainty; 22 uncertainty propagation 23 24 25 1 Introduction 15 26 27 Atomic weights provide a practical link the SI base units kilogram and mole. -
TABLE A-2 Properties of Saturated Water (Liquid–Vapor): Temperature Table Specific Volume Internal Energy Enthalpy Entropy # M3/Kg Kj/Kg Kj/Kg Kj/Kg K Sat
720 Tables in SI Units TABLE A-2 Properties of Saturated Water (Liquid–Vapor): Temperature Table Specific Volume Internal Energy Enthalpy Entropy # m3/kg kJ/kg kJ/kg kJ/kg K Sat. Sat. Sat. Sat. Sat. Sat. Sat. Sat. Temp. Press. Liquid Vapor Liquid Vapor Liquid Evap. Vapor Liquid Vapor Temp. Њ v ϫ 3 v Њ C bar f 10 g uf ug hf hfg hg sf sg C O 2 .01 0.00611 1.0002 206.136 0.00 2375.3 0.01 2501.3 2501.4 0.0000 9.1562 .01 H 4 0.00813 1.0001 157.232 16.77 2380.9 16.78 2491.9 2508.7 0.0610 9.0514 4 5 0.00872 1.0001 147.120 20.97 2382.3 20.98 2489.6 2510.6 0.0761 9.0257 5 6 0.00935 1.0001 137.734 25.19 2383.6 25.20 2487.2 2512.4 0.0912 9.0003 6 8 0.01072 1.0002 120.917 33.59 2386.4 33.60 2482.5 2516.1 0.1212 8.9501 8 10 0.01228 1.0004 106.379 42.00 2389.2 42.01 2477.7 2519.8 0.1510 8.9008 10 11 0.01312 1.0004 99.857 46.20 2390.5 46.20 2475.4 2521.6 0.1658 8.8765 11 12 0.01402 1.0005 93.784 50.41 2391.9 50.41 2473.0 2523.4 0.1806 8.8524 12 13 0.01497 1.0007 88.124 54.60 2393.3 54.60 2470.7 2525.3 0.1953 8.8285 13 14 0.01598 1.0008 82.848 58.79 2394.7 58.80 2468.3 2527.1 0.2099 8.8048 14 15 0.01705 1.0009 77.926 62.99 2396.1 62.99 2465.9 2528.9 0.2245 8.7814 15 16 0.01818 1.0011 73.333 67.18 2397.4 67.19 2463.6 2530.8 0.2390 8.7582 16 17 0.01938 1.0012 69.044 71.38 2398.8 71.38 2461.2 2532.6 0.2535 8.7351 17 18 0.02064 1.0014 65.038 75.57 2400.2 75.58 2458.8 2534.4 0.2679 8.7123 18 19 0.02198 1.0016 61.293 79.76 2401.6 79.77 2456.5 2536.2 0.2823 8.6897 19 20 0.02339 1.0018 57.791 83.95 2402.9 83.96 2454.1 2538.1 0.2966 8.6672 20 21 0.02487 1.0020 -
The Water Molecule
Seawater Chemistry: Key Ideas Water is a polar molecule with the remarkable ability to dissolve more substances than any other natural solvent. Salinity is the measure of dissolved inorganic solids in water. The most abundant ions dissolved in seawater are chloride, sodium, sulfate, and magnesium. The ocean is in steady state (approx. equilibrium). Water density is greatly affected by temperature and salinity Light and sound travel differently in water than they do in air. Oxygen and carbon dioxide are the most important dissolved gases. 1 The Water Molecule Water is a polar molecule with a positive and a negative side. 2 1 Water Molecule Asymmetry of a water molecule and distribution of electrons result in a dipole structure with the oxygen end of the molecule negatively charged and the hydrogen end of the molecule positively charged. 3 The Water Molecule Dipole structure of water molecule produces an electrostatic bond (hydrogen bond) between water molecules. Hydrogen bonds form when the positive end of one water molecule bonds to the negative end of another water molecule. 4 2 Figure 4.1 5 The Dissolving Power of Water As solid sodium chloride dissolves, the positive and negative ions are attracted to the positive and negative ends of the polar water molecules. 6 3 Formation of Hydrated Ions Water dissolves salts by surrounding the atoms in the salt crystal and neutralizing the ionic bond holding the atoms together. 7 Important Property of Water: Heat Capacity Amount of heat to raise T of 1 g by 1oC Water has high heat capacity - 1 calorie Rocks and minerals have low HC ~ 0.2 cal. -
Measuring Density
Measuring Density Background All matter has mass and volume. Mass is a measure of the amount of matter an object has. Its measure is usually given in grams (g) or kilograms (kg). Volume is the amount of space an object occupies. There are numerous units for volume including liters (l), meters cubed (m3), and gallons (gal). Mass and volume are physical properties of matter and may vary with different objects. For example, it is possible for two pieces of metal to be made out of the same material yet for one piece to be bigger than the other. If the first piece of metal is twice as large as the second, then you would expect that this piece is also twice as heavy (or have twice the mass) as the first. If both pieces of metal are made of the same material the ratio of the mass and volume will be the same. We define density (ρ) as the ratio of the mass of an object to the volume it occupies. The equation is given by: M ρ = (1.1) V here the symbol M stands for the mass of the object, and V the volume. Density has the units of mass divided by volume such as grams per centimeters cube (g/cm3) or kilograms per liter (kg/l). Sample Problem #1 A block of wood has a mass of 8 g and occupies a volume of 10 cm3. What is its density? Solution 8g The density will be = 0.8g / cm 3 . 10cm 3 This means that every centimeter cube of this wood will have a mass of 0.8 grams. -
Density Objective Learn How to Calculate Density
Density Objective Learn how to calculate density Density is a way of comparing the mass of an object to its size (volume). If an object feels heavy for its size, it has a high density. A dense object has more material (atoms) packed into a smaller area. Density cannot be measured directly, it must be calculated. The formula used to calculate density is density = mass/volume or D = m/v. The typical label for density is g/mL or g/cm3. Density is a useful tool for scientist. It is often used to help identify a pure substance. A pure substance will have one unique density. For example, each element on the periodic table has a density from any other element. If you had an unknown gas, you could calculate the density of it to identify it. The same is true for minerals- though several minerals may have the same density so other properties would also need to be used to identify the mineral. If you have ever noticed oil floating on water, that is an example of density. Objects that are less dense than water, it will float. Waters density is 1.0g/mL. 1. In general terms, describe what density is. 2. How could density be used to identify an unknown substance? 3. Density must be calculated using a math formula. What is the formula for density? 4. What is a typical label for density? *Obviously both water and ice are the same substance- so should have the same density. But does it? Then why does ice float? Suggest an explanation. -
CALCULATING DENSITY Density of Common Metals Copper 8.96 G/Cm
NAME __________________________________________ PER _______________ CALCULATING DENSITY Density of Common Metals Copper 8.96 g/cm3 Gold 19.32 g/cm3 Iron 7.87 g/cm3 Lead 11.36 /cm3 1. A substance has a mass of 1370.3 grams (g) and a volume of 71 cubic centimeters (cm3). Using the table above, what is this substance? A Iron B Lead C Gold D Copper 2. A substance has a mass of 375 grams (g) and a volume of 47.65 cm3. Using the table above, what is this substance? A Iron B Lead C Gold D Copper For questions 3 – 9, calculate the density and fill in the table. 10. What has the greater density, a cube of water measuring 1cmX1cmX1cm and having a mass of 1g, or a block of plastic measuring 2cmX3cmX1cm with a mass of 4g? A Cube of water B Block of plastic 11. A rock has a volume 57 cm3. Its mass is 14. Sam has to find the density of an 555.75 g. What is the density of this rock? irregularly shaped solid. The mass of the solid is 300.3 g. She uses water displacement to find the volume. The volume of the water alone is 100 mL. The volume of the water with the solid in it is 142 mL. What is the density of the solid? 12. Joe has to find the density of a rectangular box. He measures the width to be 6 cm, the length to be 7 cm, and the height to be 2 cm. He put the box on a balance and the mass is 15.