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Matter and Energy

Matter and Energy
Chapter 3 Matter and Energy www.ThesisScientist.comAre matter energy related • Matter is any particle with mass and volume • Energy is simply matter that is moving • 0 Kelvin is defined as the temperature when matter does not moving • So temperature is related to moving mass • Therefore: temperature and mass are related to energy • That’s why any chemistry or physics equation with energy must relate mass and temperature. www.ThesisScientist.comAround you • Everything you can see, touch, smell or taste in your room is made of matter. www.ThesisScientist.comWhat Is Matter • Matter is anything with mass. • Typically, we think of tiny little pieces of mass as atoms and molecules because those 117 elements behave Newtonian. There are over 200 smaller particles that behave Quantunian. www.ThesisScientist.comEnergy: it’s just Mass and Velocity • Electrical  Kinetic energy associated with the flow of electrical charge. • Heat or Thermal Energy  Kinetic energy associated with molecular motion. • Light or Radiant Energy  Kinetic energy associated with energy transitions in an atom. • Nuclear  Potential energy in the nucleus of atoms. • Chemical  Potential energy in the attachment of atoms or because of www.ThesisScientist.com their position.Atoms and Molecules • Atoms are the tiny particles that make up all matter. • In most substances, the atoms are joined together in units called molecules. The atoms are joined in specific geometric arrangements. www.ThesisScientist.comAny matter can exist in one of 3 States • Solid • Liquid • Gas www.ThesisScientist.comStructure Determines Properties • The atoms or molecules have different structures in solids, liquids, and gases − leading to different properties. www.ThesisScientist.comSolids • The particles in a solid are packed close together and are fixed in position.  Although they may vibrate. • The close packing of the particles results in solids being incompressible. • The inability of the particles to move around results in solids retaining their shape and volume when placed in a new container and prevents the particles from flowing. www.ThesisScientist.comSolids, Continued • Some solids have their particles arranged in an orderly geometric pattern—we call these crystalline solids. Salt and diamonds. • Other solids have particles that do not show a regular geometric pattern over a long range—we call these amorphous solids. Plastic and glass. www.ThesisScientist.comLiquids • The particles in a liquid are closely packed, but they have some ability to move around. • The close packing results in liquids being incompressible. • The ability of the particles to move allows liquids to take the shape of their container and to flow. However, they don’t have enough freedom to escape and expand to fill the container. www.ThesisScientist.comGases • In the gas state, the particles have complete freedom from each other. • The particles are constantly flying around, bumping into each other and the container. • In the gas state, there is a lot of empty space between the particles. On average. www.ThesisScientist.comGases, Continued • Because there is a lot of empty space, the particles can be squeezed closer together. Therefore, gases are compressible. • Because the particles are not held in close contact and are moving freely, gases expand to fill and take the shape of their container, and will flow. www.ThesisScientist.comMatter: is it pure or impure Matter Pure Substance Mixture Constant Composition Variable Composition Heterogeneous Homogeneous • Pure Substance = All samples are made of the same pieces in the same percentages.  Salt • Mixtures = Different samples may have the same pieces in different percentages.  Salt water www.ThesisScientist.comMixtures Heterogeneous Homogeneous 1. Made of 1. Made of multiple multiple substances, substances, but whose appears to be presence can one substance. be seen. 2. All portions of 2. Portions of a a sample have sample have the same different composition composition and properties. and properties. www.ThesisScientist.comMatter Summary www.ThesisScientist.comMatter has Properties • Physical Properties are the characteristics of matter that can be changed without changing its composition.  Characteristics that are directly observable. • Chemical Properties are the characteristics that determine how the composition of matter changes as a result of contact with other matter or the influence of energy.  Characteristics that describe the behavior of matter. www.ThesisScientist.comH O Physical verses H O Chemical 2 2 www.ThesisScientist.co mPhysical Properties Melting Point Boiling Point Electrical Thermal Magnetism Conductivity Conductivity Malleability Ductility Specific Heat Color Order Taste www.ThesisScientist.com Solid Liquid GasSome Physical Properties of Iron • Iron is a silvery solid at room temperature with a metallic taste and smooth texture. • Iron melts at 1538 °C and boils at 4428 °C. 3 • Iron’s density is 7.87 g/cm . • Iron can be magnetized. • Iron conducts electricity, but not as well as most other common metals. • Iron’s ductility and thermal conductivity are about average for a metal. • It requires 0.45 J of heat energy to raise the temperature of one gram of iron by 1°C. www.ThesisScientist.comChemical Properties Acidity Basicity Inertness Explosiveness Inflammable Flammable Oxidizing Reducing www.ThesisScientist.comSome Chemical Properties of Iron • Iron is easily oxidized in moist air to form rust. • When iron is added to hydrochloric acid, it produces a solution of ferric chloride and hydrogen gas. • Iron is more reactive than silver, but less reactive than magnesium. www.ThesisScientist.comQuiz: is it a Physical or Chemical Property • Salt is a white, granular solid = physical. • Salt melts at 801 °C = physical. • Salt is stable at room temperature, it does not decompose = chemical. • 36 g of salt will dissolve in 100 g of water = physical. • When a clear, colorless solution of silver nitrate is added to a salt solution, a white solid forms = chemical. www.ThesisScientist.comMatter has Properties, Matter can also go through Changes • Changes that alter the state or appearance of the matter without altering the composition are called physical changes. • Changes that alter the composition of the matter are called chemical changes. During the chemical change, the atoms that are present rearrange into new molecules, but all of the original atoms are still present. www.ThesisScientist.comIs it a Physical or Chemical Change • A physical change results in a different form of the same substance.  The kinds of molecules don’t change. • A chemical change results in one or more completely new substances.  Also called chemical reactions.  The new substances have different molecules than the original substances.  You will observe different physical properties because the new substances have their own physical properties. www.ThesisScientist.comPhase Changes Are Physical Changes • Boiling = liquid to gas. • Melting = solid to liquid. • Subliming = solid to gas. • Freezing = liquid to solid. • Condensing = gas to liquid. • Deposition = gas to solid. • State changes require heating or cooling the substance.  Evaporation is not a simple phase change, it is a solution process. www.ThesisScientist.comQuiz: is it a Physical or Chemical change • Evaporation of rubbing alcohol = physical. • Sugar turning black when heated = chemical. • An egg splitting open and spilling out = physical. • Sugar fermenting into alcohol = chemical. • Bubbles escaping from soda = physical. • Bubbles that form when hydrogen peroxide is mixed with blood = chemical. www.ThesisScientist.comSeparation of Mixtures • Separate mixtures based on different physical properties of the components. Physical change. Different Physical Property Technique Boiling point Distillation State of matter (solid/liquid/gas) Filtration Adherence to a surface Chromatography Volatility Evaporation Density Centrifugation and decanting www.ThesisScientist.comDistillation: different boiling points www.ThesisScientist.comFiltration: different solubility's www.ThesisScientist.comSummary • Moving Matter has Energy. Motion is related to temperature. All energy formulas are relations between mass and temperature • Matter has 3 states States/Properties/Change are all related to temperature • Matter has properties and how much you have • Matter can change www.ThesisScientist.comLaw of Conservation of Mass • Antoine Lavoisier • “Matter is neither created nor destroyed in a chemical reaction.” • The total amount of matter present before a chemical reaction is always the same as the total amount after. • butane + oxygen  carbon dioxide + water 58 grams + 208 grams  176 grams + 90 grams 266 grams = 266 grams www.ThesisScientist.comLaw of Conservation of Energy • ―Energy can neither be created nor destroyed.” • The total amount of energy in the universe is constant. There is no process that can increase or decrease that amount. • Note: neither Mass nor Energy are ever destroyed www.ThesisScientist.comEnergy • The Fundamental Principle of the Universe is Energy • From the Greeks to Newton to Quantum Mechanics Energy is known as the capacity to do work and is simply calculated by knowing the mass and velocity of a particle. • The harder you swing an ax the faster you can fall a tree. • Guess what happens when you walk into a wall .005 mph or 500 mph www.ThesisScientist.comEnergy: it’s just Mass and Velocity • Electrical  Kinetic energy associated with the flow of electrical charge. • Heat or Thermal Energy  Kinetic energy associated with molecular motion. • Light or Radiant Energy  Kinetic energy associated with energy transitions in an atom. • Nuclear  Potential energy in the nucleus of atoms. • Chemical  Potential energy in the attachment of atoms or because of www.ThesisScientist.com their position.To get Energy (electrical, thermal, light, nuclear, chemical) • You take slow moving particles and make them move faster As slow moving water falls, gravity pulls it faster. The water falls on top of a turbine, which moves a coil in a magnet to generate electricity. www.ThesisScientist.comTo get Energy (electrical, thermal, light, nuclear, chemical) • You take slow moving particles and make them move faster www.ThesisScientist.comTo get Energy (electrical, thermal, light, nuclear, chemical) • You take slow moving particles and make them move faster Binding energy is simply the amount of energy (and mass) released, when free nucleons join to form a nucleus; a gluon is released or absorbed Einstein's massenergy equivalence formula E = mc² can be used to compute the binding energy www.ThesisScientist.comKinds of Energy Kinetic and Potential • Potential energy is energy that is stored; slow moving  Water flows because gravity pulls it downstream.  However, the dam won’t allow it to move, so it has to store that energy. • Kinetic energy is energy of motion, or energy that is being transferred from one object to another; fast moving.  When the water flows over the dam, some of its potential energy is converted to kinetic energy of motion. www.ThesisScientist.comThere’s No Such Thing as a Free Ride When atoms contact each other, frictions is produced. You will often notice friction as sound or heat. So instead of useful energy, ―antienergy‖ friction slows your car down. www.ThesisScientist.comUnits of Energy • Calorie (cal) is the amount of energy needed to raise one gram of water by 1 °C. kcal = energy needed to raise 1000 g of water 1 °C. food calories = kcals. Energy Conversion Factors 1 calorie (cal) = 4.184 joules (J) 1 Calorie (Cal) = 1000 calories (cal) 6 1 kilowatthour (kWh) = 3.60 x 10 joules (J) www.ThesisScientist.comEnergy Use 2008 Energy Energy Energy Required Required to Used by to Raise Light 100W Average Temperature of 1 g Bulb for 1 U.S. Citizen Unit of Water by 1°C Hour in 1 Day 5 8 joule (J) 4.18 3.6 x 10 9.0 x 10 4 8 calorie (cal) 1.00 8.60 x 10 2.2 x 10 3 5 Calorie (Cal) 1.00 x 10 86.0 2.2 x 10 6 2 kWh 1.1 x 10 0.100 2.50 x 10 www.ThesisScientist.comEx 3.5, A candy bar has 225 Cal, convert to Joules 1. Write down the Given Given: 225 Cal 3 sig figs quantity and its unit. 2. Write down the quantity Find: J you want to Find and unit. 3. Write down the appropriate Conversion 1 Cal = 1000 cal Conversion Factors. Factors: 1 cal = 4.184 J 4. Write a Solution Map. Solution Cal cal J Map: 1000 cal 4.184 J 1 Cal 1 cal 5. Follow the solution map to Solution: Solve the problem. 1000 cal 4.184 J 5 225 Cal 9.4110 J 1 Cal 1 cal 5 6. Significant figures and Round: 225 Cal = 9.41 x 10 J round. 3 significant figures Units and magnitude are 7. Check. wwwCheck .ThesisSc: ientist.com correct.Chemical Potential Energy • The amount of energy stored in a material is its chemical potential energy. • The stored energy arises mainly from  the attachments between atoms in the molecules  the attractive forces between molecules. www.ThesisScientist.comExothermic Processes • When a change results in the release of energy it is called an exothermic process. • An exothermic chemical reaction occurs when the reactants have more chemical potential energy than the products. • The excess energy is released into the surrounding materials, adding energy to them.  Often the surrounding materials get hotter from the energy released by the reaction. www.ThesisScientist.comAn Exothermic Reaction Surroundings reaction Reactants Amount of energy released Products www.ThesisScientist.com Potential energyEndothermic Processes • When a change requires the absorption of energy it is called an endothermic process. • An endothermic chemical reaction occurs when the products have more chemical potential energy than the reactants. • The required energy is absorbed from the surrounding materials, taking energy from them.  Often the surrounding materials get colder due to the energy being removed by the reaction. www.ThesisScientist.comAn Endothermic Reaction Surroundings reaction Products Amount of energy absorbed Reactants www.ThesisScientist.com Potential energyTemperature Scales 100°C 373 K 212°F 671 R Boiling point water 298 K 75°F 534 R Room temp 25°C 0°C 273 K 32°F 459 R Melting point ice 38.9°C 234.1 K 38°F 421 R Boiling point mercury 183°C 90 K 297°F 162 R Boiling point oxygen BP helium 269°C 4 K 452°F 7 R 273°C 0 K 459 °F 0 R Absolute zero Celsius Kelvin Fahrenheit Rankine www.ThesisScientist.comFahrenheit vs. Celsius • A Celsius degree is 1.8 times larger than a Fahrenheit degree. • The standard used for 0° on the Fahrenheit scale is a lower temperature than the standard used for 0° on the Celsius scale. F 32 C  1.8 www.ThesisScientist.comThe Kelvin Temperature Scale • Both the Celsius and Fahrenheit scales have negative numbers.  Yet, real physical things are always positive amounts • The Kelvin scale is an absolute scale, meaning it measures the actual temperature of an object. • 0 K is called absolute zero, all molecular motion stops.  0 K = 273 °C = 459 °F.  Absolute zero is a theoretical value obtained by following patterns mathematically. www.ThesisScientist.comKelvin vs. Celsius • The size of a ―degree‖ on the Kelvin scale is the same as on the Celsius scale.  Although technically, we don’t call the divisions on the Kelvin scale degrees; we call them kelvins  That makes 1 K 1.8 times larger than 1 °F. • The 0 standard on the Kelvin scale is a much lower temperature than on the Celsius scale. • When converting between kelvins and °C, remember that the kelvin temperature is always the larger number and always positive K  C 273 www.ThesisScientist.comExample 3.7—Convert –25 °C to Kelvins 1. Write down the Given Given: 25 °C quantity and its unit. units place Find: 2. Write down the quantity K you want to Find and unit. 3. Write down the appropriate Equation: K = ° C + 273 Equations. 4. Write a Solution Map. Solution ° C K Map: K   C 273 5. Follow the solution map to Solution: Solve the problem. K (25 C) 273 258 K 6. Significant figures and Round: 258 K units place round. Units and magnitude are 7. Check. www.TCheck hesisScien :tist.com correct.Example 3.8—Convert 55° F to Celsius 1. Write down the Given Given: 55 °F units place quantity and its unit. and 2 sig figs Find: 2. Write down the quantity ° C you want to Find and unit. 3. Write down the appropriate Equation: F 32 C  Equations. 1.8 4. Write a Solution Map. Solution ° F ° C Map: F32 C  1.8 5. Follow the solution map to Solution: Solve the problem.  55 F 32 C  12.778 C 1.8 6. Significant figures and Round: 12.778 °C = 13 °C round. units place and 2 sig figs Units and magnitude are 7. Check. www.TCheck hesisScien :tist.com correct.Example 3.9—Convert 310 K to Fahrenheit 1. Write down the Given Given: 310 K units place quantity and its unit. and 3 sig figs Find: 2. Write down the quantity °F you want to Find and unit. 3. Write down the appropriate Equation: F32 K = °C + 273 C  Equations. 1.8 4. Write a Solution Map. Solution K °C °F Map: °C = K 273 F  1.8C 32 5. Follow the solution map to Solution: Solve the problem. C  310 273 37 C F  1.837 C 32 98.6 F 6. Significant figures and Round: 98.6 °F = 99 °F round. units place and 2 sig figs 7. Check. www.TCheck hesisScien :tist.com Units and magnitude are correct.Practice—Convert 0 °F into Kelvin www.ThesisScientist.comPractice—Convert 0 °F into Kelvin, Continued °C = 0.556(°F32) °C = 0.556(032) °C = 18 °C K = °C + 273 K = (18) + 273 K = 255 K www.ThesisScientist.comHeat Capacity • Heat capacity is the amount of heat a substance must absorb to raise its temperature by 1 °C. cal/°C or J/°C. Metals have low heat capacities; insulators have high heat capacities. • Specific heat = heat capacity of 1 gram of the substance. cal/g°C or J/g°C. Water’s specific heat = 4.184 J/g°C for liquid. Or 1.000 cal/g°C. It is less for ice and steam. www.ThesisScientist.comSpecific Heat Capacity • Specific heat is the amount of energy required to raise the temperature of one gram of a substance by 1 °C. • The larger a material’s specific heat is, the more energy it takes to raise its temperature a given amount. • Like density, specific heat is a property of the type of matter.  It doesn’t matter how much material you have.  It can be used to identify the type of matter. • Water’s high specific heat is the reason it is such a good cooling agent.  It absorbs a lot of heat for a relatively small mass. www.ThesisScientist.comSpecific Heat Capacities Substance Specific Heat J/g°C Aluminum 0.903 Carbon (dia) 0.508 Carbon (gra) 0.708 Copper 0.385 Gold 0.128 Iron 0.449 Lead 0.128 Silver 0.235 Ethanol 2.42 Water (l) 4.184 Water (s) 2.03 Water (g) 2.02 www.ThesisScientist.comHeat Gain or Loss by an Object • The amount of heat energy gained or lost by an object depends on 3 factors: how much material there is, what the material is, and how much the temperature changed. Amount of Heat = Mass x Heat Capacity x Temperature Change q = m x C x DT www.ThesisScientist.comExample 3.10—Calculate Amount of Heat Needed to Raise Temperature of 2.5 g Ga from 25.0 to 29.9 °C 1. Write down the Given Given: m = 2.5 g, T = 25.0 °C, 1 quantity and its unit. T = 29.9 °C, C = 0.372 J/g°C 2 Find: 2. Write down the quantity q, J you want to Find and unit. 3. Write down the appropriate Equation: q mCDT Equations. 4. Write a Solution Map. Solution m, C, DT q Map: q mCDT 5. Follow the solution map to Solution: Solve the problem. J q 2.5 g0.372 29.9 25.0C gC q 4.557 J 6. Significant figures and Round: 4.557 J = 4.6 J round. 2 significant figures Units and magnitude are 7. Check. wwwCheck .ThesisSc: ientist.com correct.Practice—Calculate the Amount of Heat Released When 7.40 g of Water Cools from 49° to 29 °C www.ThesisScientist.comPractice—Calculate the Amount of Heat Released When 7.40 g of Water Cools from 49° to 29 °C, Continued Given: • Sort T = 49 °C, T = 29 °C, m = 7.40 g 1 2 Information Find: q, J Solution Map: • Strategize C m, DT q s q  m CΔT s q = m ∙ C ∙ DT s Relationships: C = 4.18 J/gC (Table 3.4) s Solution: • Follow the q m CΔT s concept DT  T T 2 1 J  plan to  7.40 g 4.18  20 C DT  29 C 49C gC solve the  20 C 2 problem.618.64 J6.210 J Check: • Check. The unit and sign are correct. www.ThesisScientist.com