energy matter bonding

www.unit5.org/chemistryEnergy and MatterUnit 2

www.unit5.org/chemistry

Guiding QuestionsWhy do substances boil or freeze at different temperatures? Why do we put salt on the roads in the winter?

Why does sweating cool us?

What is energy?

How do we measure energy?

Table of ContentsMatter and Energy(13) Introduction - Bonding(14) Temperature vs. Heat(11) Density (6) Carbon Dioxide & Monoxide (4) Archimedes Principle (3) Galilean Thermometer(11) Golf Ball Lab(15) Solid, Liquid, and Gas (3) Heating Curve(13) Classification of Matter (6) Crystalline Structure(10) Allotropes(9) Alloys(4) Separation Techniques(11) Distillation(2) Centrifugation(3) Electrolysis(5) Properties of Matter(6) Energy(11) Exothermic vs. Endothermic(29) Calorimetry(12) Nuclear Energy

Lecture Outline Energy and MatterKeys

Lecture Outline Energy and MatterLecture Outline Energy and Matterstudent notes outlinetextbook questionshttp://www.unit5.org/chemistry/Matter.htmltextbook questionstext

Vocabulary - Energy and MatterKeys

Vocabulary: Matter and Energy Vocabulary: Matter and Energy http://www.unit5.org/chemistry/Matter.html

Matter and Energy

Chemistry of MatchesP4S3 + KClO3 P2O5 + KCl + SO2tetraphosphorustrisulfidepotassiumchloratediphosphoruspentaoxidepotassiumchloridesulfurdioxideDThe substances P4S3 and KClO3 are both present on the tip of a strike anywhere match. When the match is struck on a rough surface, the two chemicals (reactants) ignite and produce a flame. Charles H.Corwin, Introductory Chemistry 2005, page 182Safety matchesThe products from this reaction are P2O5, KCl, and SO2,the last of which is responsible for the characteristic sulfur smell.

Strike anywhere matchesThe substances P4S3 and KClO3 are separated. The P4S3 is onthe matchbox cover. Only when the chemicals combine do they react and produce a flame.

block of wood: length = 2.0 m width = 0.9 m height = 0.5 mblock of wood: force = 45 N

Force versus PressureArea = 0.9 m x 2.0 m = 1.8 m2Area = 0.5 m x 2.0 m = 1.0 m2Area = 0.5 m x 0.9 m = 0.45 m2block of wood: length = 2.0 m width = 0.9 m height = 0.5 m25 N/m2 45 N/m2 100 N/m2 Herron, Frank, Sarquis, Sarquis, Schrader, Kulka, Chemistry, Heath Publishing,1996, page Section 6.1

PressureWhich shoes create the most pressure?

During aphysical changea substance changes some physical propertyH2O

but it is still the same material with the same chemical composition.H2Ogassolidliquid

Chemical Property:The tendency of a substance to change into another substance.caused by iron (Fe) reacting with oxygen (O2) to produce rust (Fe2O3)Steel rusting:4 Fe + 3 O2 2 Fe2O3

Chemical Change:Any change involving a rearrangement of atoms.

Chemical Reaction:The process of a chemical change...

During achemical reactionnew materials are formed by a change in the way atoms are bonded together.

Physical and Chemical PropertiesExamples of Physical PropertiesBoiling point Color SlipperinessElectrical conductivity

Melting point TasteOdorDissolves in water

Shininess (luster) SoftnessDuctilityViscosity (resistance to flow)

Volatility HardnessMalleabilityDensity (mass / volume ratio)Examples of Chemical PropertiesBurns in air Reacts with certain acidsDecomposes when heated

Explodes Reacts with certain metalsReacts with certain nonmetalsTarnishes Reacts with waterIs toxicRalph A. Burns, Fundamentals of Chemistry 1999, page 23Chemical properties can ONLY be observed during a chemical reaction!

The formation of a mixtureThe formation of a compoundChemical ChangePhysical Change

Physical & Chemical ChangesLimestone,CaCO3crushingPHYSICALCHANGECrushed limestone,CaCO3heatingCHEMICALCHANGECO2CaOLime andcarbon dioxide,CaO + CO2

O2H2OH2O2Light hastens the decomposition of hydrogen peroxide, H2O2. The dark bottle in which hydrogen peroxide is usually storedkeeps out the light, thus protecting the H2O2 from decomposition.Sunlight energy

Percentage CompositionKeys

Percentage Composition Percentage Composition http://www.unit5.org/chemistry/Matter.html

PropertiesKeys

Properties of Matter Properties of Matter http://www.unit5.org/chemistry/Matter.html

Three Possible Types of BondsCovalent e.g. H2Polar Covalent e.g. HCl

Ionic e.g. NaCl

Metallic BondingMetallic bonding is the attraction between positive ions and surrounding freely mobile electrons. Most metals contributemore than one mobile electron per atom.Bailar, Jr, Moeller, Kleinberg, Guss, Castellion, Metz, Chemistry, 1984, page 245

Shattering an Ionic Crystal; Bending a MetalBailar, Jr, Moeller, Kleinberg, Guss, Castellion, Metz, Chemistry, 1984, page 248An ionic crystalA metalNo electrostatic forces of repulsion metal is deformed (malleable)Electrostatic forces of repulsion ForceForcebroken crystal

Properties of Ionic CompoundsCrystalline solidsHard and brittleHigh melting pointsHigh boiling pointsHigh heats of vaporizationHigh heats of fusionGood conductors of electricity when moltenPoor conductors of heat and electricity when solidMany are soluble in water

Chemical BondsIncreasing ionic characterRalph A. Burns, Fundamentals of Chemistry 1999, page 229 between two identical nonmetal atoms are non-polar covalent. between two different nonmetal atoms are polar covalent. between nonmetals and reactive metals are primarily ionic.

Chemical BondsIncreasing ionic characterRalph A. Burns, Fundamentals of Chemistry 1999, page 229 between two identical nonmetal atoms are nonpolar covalent. between two different nonmetal atoms are polar covalent. between nonmetals and reactive metals are primarily ionic.

Covalent vs. IonicCovalentTransferelectrons(ions formed)+ / -BetweenMetal andNonmetalStrongBonds(high melting point)Shareelectrons(polar vs. nonpolar)

BetweenTwoNonmetalsWeak Bonds(low melting point)AlikeDifferentElectronsareinvolvedChemicalBondsIonicDifferentTopicTopic

Photoelectric GeneratorSolar Calculator

* Chemical change has always been part of the Universe, even before human beings evolved. Indeed, scientists believe that life began on Earth as a result of complex chemicals reproducing themselves over billions of years. Chemistry is a physical science; it lies between the biological sciences helping to explain many of lifes processes, and the laws of physics, which include matter and energy. Chemical processes are constantly occurring within us when our bodies move, a series of chemical reactions takes place to give the muscles the energy that is taken in from food. Many species of the animal world make use of chemistry to defend themselves, to kill their prey, and to build fragile structures that have incredible strength. Modern methods of chemical analysis have led to greater understanding of the chemistry of nature, so that it is possible to identify those chemical compounds that produce the color, taste, and smell of a flower or a fruit.

Eyewitness Science Chemistry , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 8

http://farm2.static.flickr.com/1423/802816175_f0041f3086_o.jpg*What you should learn:Chemists look at ways of describing and classifying matter in terms of physical and chemical properties for the purposes of a) understanding the universe and b) manipulating the world around us Studying the nature of chemicals allows one to solve real world problems

More Specifically...:Describe the general properties of matter. Identify common elements by chemical symbols Distinguish between physical and chemical properties of matter. Important physical properties: density, conductivity, melting point, boiling point, malleability, and ductility. Classify matter according to whether it is an element, a compound, homogeneous mixture or heterogeneous mixture, pure or impure, solution, colloid, or suspension State the law of conservation of mass Perform calculations that involve the law of conservation of mass Perform density calculations Define the mole and use dimension analysis to convert between Grams and moles Particles and moles Particles and grams

What you should learn:Physical properties can be explained and predicted by intermolecular interactions The amount of energy required to induce a physical change can be quantified. Intermolecular forces determine the relative amount of energy required for physical changes When energy is absorbed by a system, another system has lost an equivalent amount of energy (Law of conservation of energy).

More Specifically...:Pure Substances Use intermolecular forces to explain differences in physical properties Interpret phase diagrams Mixtures Interpret solubility graphs Predict solubility and miscibility using the rule "Like dissolves like" Explain what is meant by unsaturated, saturated and supersaturated solutions Describe the effect of temperature and pressure on solubility Describe the process of solvation for ionic and covalent substances Write dissociation reactions Identify strong, weak and non-electrolytes Describe the role of electrolytes in the body Explain causes of freezing point depression, boiling point elevation, and vapor pressure reduction

Review Concepts Describe how energy is gained or lost during changes of state Calculate enthalpy change for phase changes using heat of vaporization and heat of formation State that the temperature of a substance does not change as it undergoes a change in state Determine when to use q = mCpT and when to use q = m H Graph and interpret a heating/cooling curve

What you should learn:Unit outlineEnergy can neither be created nor destroyed only transformed from one form into another. If an object loses energy something else must gain an equivalent amount of energy and that change in energy will result in changes in the molecules; their motion (kinetic energy) and/or potential energy. The motion of molecules and atoms explains energy transfer and changes in volume and pressure.

More Specifically...:Energy, Enthalpy, Heat and Temperature Classify reactions as endothermic or exothermic Classify sources of energy as potential, kinetic, or mass-energy List the kinds of energy transformed in a given situation Distinguish between heat and temperature. Convert between different units of temperature Calculate heat required to change the temperature of substances using Q=mC?T and q = m?H Describe how energy is gained or lost during changes of state Calculate enthalpy change for phase changes using heat of vaporization and heat of formation State that the temperature of a substance does not change as it undergoes a change in state Determine when to use q = mC?T and when to use q = m?H Graph and interpret a heating/cooling curve Distinguish between Heat of vaporization Heat of fusion Interaction of matter and energy State the law of energy-mass conservation (E=mc2) Use the four indicators of chemical change (gas formation, precipitation, heat and light, color change) to determine whether a physical change or chemical change has taken place Describe the three states of matter in terms of energy and organization of molecules

*Matter and Energy Study Questions

1. What is chemistry?2. What is matter?3. Define mass.4. What are the two aspects of structure?5. Contrast qualitative and quantitative.6. Compare mixtures and substances.7. What is a mixture?8. You have a mixture of salt and sand. How can you separate them?9. You have a mixture of iron and sugar. How can you separate them?10. How does a solution differ from a suspension?11. Define solute.12. Define solvent.13. What is a phase?14. What phases are found in a cup of brewing tea?15. Describe a heterogeneous mixture.16. Compare elements and compounds.17. What are physical properties?18. What are chemical properties?19. Is density an intensive or extensive property?20. Is mass an intensive or extensive property?21. Is temperature an intensive or extensive property?22. Is volume an intensive or extensive property?23. Compare solids and glasses.24. Describe the molecular movement in solids, liquids, and gases.25. What are the signs a chemical reaction is occurring?26. When is a chemical property observed?27. What is a system?28. What type of energy changes happen in chemical systems?29. What are the three types of energy transfers found in chemistry?30. Compare exothermic and endothermic reactions.31. Describe the energy changes involved in getting energy from the sun to you vocal cords.32. The element oxygen is a gas that makes us 20% of Earths atmosphere. It is also the most abundant element in Earths crust, yet Earths crust is not a gas. Explain this apparent conflict.33. On cool evenings a campfire warms the body and spirit. Is the burning of logs an exothermic or endothermic reaction?34. What is the solvent in an aqueous solution of NaCl?35. What is energy, and why is it important in chemistry?36. How does a qualitative observation differ from a quantitative observation?37. Is the processing of French fries in your body an exothermic or endothermic process?38. Which of the following has the lowest boiling point: oxygen, water, and salt?39. Which of these compounds have the highest melting point: oxygen, water, and salt?40. What does the formula C2H6O tell you about the substance it represents? Be as specific as possible. *ALL students should; Recall a definition of chemistry Understand the process and stages of scientific (logical) problem solving Recall the three states of matter and their general properties Recall the methods for converting between the three different states of matter Understand and recall definitions for physical and chemical change Be able to recall and use the formula for calculating energy using specific heat capacity Know the difference between elements, mixtures and compounds including the difference between heterogeneous and homogeneous mixtures Understand and be able to use scientific notation (standard form) Recall and use some SI units Be able to interconvert between units using conversion factors Recall, and be able to use the rules for determining significant figures and rounding off Learn, and be able to use, formula for the conversion of the three different temperature units studied in TOPIC 1 Learn, and be able to use the formula for density Understand the differences between, and be able to apply, the concepts of accuracy and precision

***The substances P4S3 and KClO3 are present on the tip of a match. When thematch is struck on a rough surface, the two chemicals (reactants) ignite and produce a flame. The products from this reaction are P2O5, KCl, and SO2,the last which is responsible for the characteristic sulfur smell.

Safety matches have the P4S3 on the matchbook or box. This is the red strip you need to rub the match against to get it to ignite.Strike anywhere matches contain both reactants on the match head.

[NOTE: Red phosphorus is an important ingredient for making methamphetamines and may be reason high school teachers are not allowed to purchase it.]

A good demonstration is the SMOKE reaction: combine 6 g KClO3 + 2 g table sugar (stir gently) and place in an evaporating dish. Add 1 drop of [H2SO4]. The sugar will rapidly burn! Do this reaction only in a fume hood. It will produce lots of smoke. The rapidcombustion of the sugar is due to the fact that the potassium chlorate is an oxidizer (contains oxygen). Oxygen is not the limiting reactant for this demonstration.

I also show the DEHYDRATION OF SUGAR demonstration. I fill a 250 mL beaker with table sugar, add ~5 mL tap water and stir with a glass stirring rod. Finally, add ~50 mL concentrated sulfuric acid. The sugar will be rapidly dehydrated (leaving only a carbon tower). DO NOT touch the burned sugar as it contains excess sulfuric acid.

This reaction is a much slower burning of table sugarnot enough oxygen present.**The pressure exerted by a wood block when it stands on its smallest face is nearly four times the pressure exerted when it stands on its widest face.

*Consider shoes: The difference between force and pressure is obvious if a woman wearing high-heeled shoes accidentally steps on your toes with the heel. You feel the pressure (and the pain). Some people who live in northern latitudes wear snowshoes to walk in deep snow.*http://216.70.123.96/images/uploads/iceberg.jpg PHOTO of iceberg**Photo: http://images.google.com/imgres?imgurl=http://lh3.google.com/_aY_0d2zXNW4/RXHxKerci-I/AAAAAAAAAAg/gSRVWgC4BKk/s800/_DSC0167.jpg&imgrefurl=http://picasaweb.google.com/lh/photo/HW7I5kPuUN2Mo57PJPG9RA&h=529&w=800&sz=96&hl=en&start=3&um=1&tbnid=JY9_ZpLYaeOgwM:&tbnh=95&tbnw=143&prev=/images%3Fq%3Dsteel%2Brusting%26um%3D1%26hl%3Den%26rlz%3D1T4RNWK_enUS255US257*http://www.pdsm.wpafb.af.mil/toprac/atoms_full_std.gif*****The crushing of limestone is a physical change; it does not alter the chemical composition of the limestone. The heating of limestone is a chemical change; the limestone decomposes into two other substances, lime and carbon dioxide.

http://www.fi.edu/fellows/payton/rocks/expert/graphics/LIMESTON.JPGhttp://www.greenleafsupply.com/images/Dolomiteb.jpg****In a covalent (non-covalent) bond, electrons are shared equally by the atoms. In a polar covalent bond. the electrons are more attracted to one atom (the more electronegative element) than the other.In an ionic bond, an electron(s) is transferred from a metal atom to a non-metal. The result is a cation (+ charged ion) and an anion (- charged ion).

An analogy: a covalent bond is similar to ideal communism (everyone has an equal share).Everyone gets $1000.a polar covalent bond is similar to socialism (everyone gets something, but some have more than others).Some people are wealthy (millionaires) and other people are middle class.Two different areas of a city: a wealthy area and a poor area. No one is starving.an ionic bond is similar to comparing a first and third world countryThe third world country has nothing (people are starving) while the first world has everything (people are obese from over-eating). *In a metallic bond, the metal atoms have excess valence electrons and are trying to get rid of them to achieve a stable octet. An analogy is playing 'hot potato' - no atom wants to extra electrons and they are free to 'float' around. *In an ionic crystal, the ions are lined up as to have negative charge surrounding positive charge and vice versa. The ions are locked in a rigid lattice structure or crystalline arrangement. When a force is applied, the ions shift, and repel each other when like charges are next to each other. The electrostatic forces of repulsion cause the ionic crystal to split or fracture (cleavage).

****Chemical bonds are formed by sharing (covalent bonds) or transferring (ionic bonds) electrons. An ionic bond is stronger than a covalent bond. This can be shown by looking at the melting point of a substance. A high melting point indicates a strong bond, while a low melting point indicates a weak bond. For example: salt on fries in an oven doesn't melt at 450oF (salt is an ionic bond) sugar crystals will melt at relatively low temperatures (sugar is a covalent bond)A polar covalent bond is stronger than a non-polar covalent bond.

A covalent bond can be a single bond (formed by sharing two electrons);a double bond (formed by sharing four electrons); or a triple bond (formed by sharing six electrons).*Chemical bonds are formed by sharing (covalent bonds) or transferring (ionic bonds) electrons. An ionic bond is stronger than a covalent bond. This can be shown by looking at the melting point of a substance. A high melting point indicates a strong bond, while a low melting point indicates a weak bond. For example: salt on fries in an oven doesn't melt at 450oF (salt is an ionic bond) sugar crystals will melt at relatively low temperatures (sugar is a covalent bond)A polar covalent bond is stronger than a non-polar covalent bond.

A covalent bond can be a single bond (formed by sharing two electrons);a double bond (formed by sharing four electrons); or a triple bond (formed by sharing six electrons).

**Electromagnetic radiation strikes the surface of the metal, ejecting electrons from the metal and creating an electric current.

The photoelectric effect is the emission of electrons by certain metals when light shines on the metals. This phenomenon only occurs at certain wavelengths and therefore cannot be explained by the wave theory of light.

What property of light causes the electrons to be knocked loose from the metal?(Light contains particles called photons that knock the electrons loose.)

What is a useful application of the photoelectric effect?(Production of photoelectric or solar cells.)

energy matter bonding

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