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Ch 1& 2 ppt
- 1.
- 2. ChemistryDefinition – studyof the composition and properties of matter and the energy transformations accompanying changes in the structure of matter
- 3. Major Branches ofChemistryInorganic Chemistry – Study of all the elements other than Carbon
- 4. Organic Chemistry –Study of compounds containing carbon
- 5. Biochemistry – studyof chemical processes in living things
- 6. NuclearChemistry – studyof radioactivity, the nucleus and the changes that the nucleus undergoes Democritus AristotleEarly Greek Theories400 B.C. - Democritus thought matter could not be divided indefinitely.
- 7. This led tothe idea of atoms in a void.
- 8. 350 B.C -Aristotle modified an earlier theory that matter was made of four “elements”: earth, fire, water, air.
- 9. Aristotle was wrong. However, his theory persisted for 2000 years.The Rise of Modern ChemistryThe Greek idea of the 4 basic elements was not disputed until the mid 1600sRobert Boyle proposed that elements are substances that cannot be chemically decomposed into simpler substances. Earth, air, fire and water could not be called elementsIn 1774 Joseph Priestly discovered a gas in which substances burned easily, Antoine Lavoisier named the gas OxygenBoylePriestly
- 10. John Dalton1800 -Daltonproposed a modern atomic model based on experimentation not on pure reason.All matter is made of atoms.
- 11. Atoms of anelement are identical.
- 12. Each element hasdifferent atoms.
- 13. Atoms of differentelements combine in constant ratios to form compounds.
- 14. Atoms are rearrangedin reactions.
- 15. His ideas accountfor the law of conservation of mass (atoms are neither created nor destroyed) and the law of constant composition (elements combine in fixed ratios).Reaction of the Day 9/9/10Table sugar + sulfuric acid Carbon + H20H2SO4C12H22011(s) 12 C (s) + 11 H2O (g)
- 16. Ch 2 -MatterMatter – anything that takes up space and has mass
- 17. Chemical and PhysicalProperties of MatterPhysical properties – color, shape, texture, odor, taste, electrical conductivity, and densitydensity – how closely packed the molecules are malleable – substances that can be easily hammered into shapesductility – substances that can be stretched into wiresconductivity – substances that can transfer heat or electricityChemical properties – describe how matter acts in the presence of other materials
- 18. What is eachpicture modeling? Density, malleability, ductility, conductivity
- 19. Physical or ChemicalChange
- 20. Physical vs. ChemicalChangePhysical ChangeAtoms do not rearrangeOnly physical properties change. Chemical properties do not change.Physical changes are generally easy to reverse.No energy is produced by the substance.Chemical ChangeAtoms are rearranged into different moleculesBoth physical and chemical properties are changedChanges are not reversible without another reactionEnergy is often produced ( fire or heat, for example)
- 21. Identify each ofthe following as a Physical or Chemical Change.Put a P next to Physical Changes and a C next to Chemical Changes1. A piece of wood burns to form ash. 2. Water evaporates into steam. 3. A piece of cork is cut in half.4. A bicycle chain rusts. 5. Food is digested in the stomach. 6. Water is absorbed by a paper towel. 7. Hydrochloric Acid reacts with zinc. 8. A piece of an apple rots on the ground. 9. A tire is inflated with air. 10. A plant turns sunlight, CO2, and water into sugar and oxygen. 11. Sugar dissolves in water. 12. Eggs turn into an omelette. 13. Milk sours. 14. A popsicle melts. 15. Turning brownie mix into brownies.
- 22. HomeworkRead pgs 21- 28http://www.quia.com/quiz/303980.html
- 23. The Division ofMatterTwo major categories: 1) pure substances - consists of only one type of matter, which cannot be separated into other kinds of matter by any physical processes. Ex: Olive oil 2) mixtures – material that can be separated by physical means into two or more pure substances. Ex: Oil and vinegar salad dressing
- 24. Two Types ofMixturesHeterogeneous – physical combinations of pure substances that show two or more distinct phases. Ex: oil & vinegar dressing, granite has quartz & micaHomogeneous – (solution) physical combinations of pure substances that show one distinct phase, the physical properties appear to be the same throughout. Ex: dough & air
- 25. Elements and TheirSymbolsElement - pure substance that cannot be broken down into simpler substances
- 26. Elements and TheirSymbolsAtoms – smallest particles that maintain the physical and chemical characteristics of an elementMonoatomic elements – elements that do not naturally combine or bond together. Ex: Ne, He, ArDiatomic elements - elements that bond into two-atom units. Ex: O2, H2Polyatomic elements – elements composed of multi-atom units. Ex: S8
- 27. Elements and TheirSymbolsSymbol – letter given to represent the name of each elementH – hydrogenO – OxygenCa – CalciumMg – MagnesiumMn – ManganeseNa - Sodium
- 28. Compounds and TheirFormulasCompounds are made up of atoms from two or more different elements, chemically bonded togetherFormulas tell the type and number of atoms that are present in compounds Common Compounds and Their Formulas
- 29. Sample ProblemsHow manyatoms of each element are present in each of the following groups? Na2S2O3Mg(NO3)25 Fe2O3
- 30. MoleculeThe smallest independentunits of compounds Consist of two or more atoms that are chemically bonded togetherEx: H20, NH3, H2SO4Homework: Section Review Questions 2A, pg 29, #1-3
- 31. 2B Energy inMatterEvery chemical reaction either releases or absorbs energyExothermic reactions – release energy (get hot) Ex: lighting a matchEndothermic reactions – absorb energy (get cold) Ex: ice pack
- 32. Energy – theability to do workThere are many forms of energyChemistry is concerned with the relationship among chemical, thermal, electrical and nuclear energy
- 33. Energy ConservationThermodynamics –the study of energy flowFirst Law of Thermodynamics or Law of Conservation of Mass-Energy –matter and energy can neither be created nor destroyed, simply changed from one form to anotherSecond Law of Thermodynamics – during any energy transformation, some energy goes to an unusable form
- 34. Energy ConservationEntropy –randomness or disorder of a systemThere is a tendency for all natural processes to increase in entropy (disorder)
- 35. Heat, Energy &TemperatureKinetic Energy – energy of motion All matter contains particles that are movingThermal Energy – sum of all the kinetic energy of an objectTemperature measures the average kinetic energy of all the particles in a sampleHeat – thermal energy that is transferred from one object to anotherAmount of heat transfered between objects is determined by the temperature difference between then and the mass of the hotter object
- 36. Which contains morethermal energy?A teaspoon of boiling water or a bathtub full of lukewarm water
- 37. The Measurement ofEnergyJoule – standard unit of measurement for energyBTU – English unit of measurement for thermal energy, the amount of heat required to raise one pound of water by one degree FahrenheitCalorie – amount of energy required to raise the temperature of one gram of water one degree Celsius1 cal = 4.184 J
- 38. Temperature ScalesCelsius scale– freezing point of water is 0◦ C boiling point of water is 100 ◦ CKelvin scale – uses absolute zero (point at which molecules no longer move) as the zero point freezing point of water is 273 K boiling point of water is 373 KFahrenheit scale – freezing point of water is 32◦F boiling point of water is 212 ◦F
- 40. Conversion between scalesK= ◦ C + 273 ◦ C = K - 273 ◦ F = (1.8 x ◦ C) ◦ C = (◦ F-32)/1.8Sample Problem: The weatherman announces that the high for the day is expected to be 33 ◦ C What is this temperature on the Kelvin scale and the Fahrenheit scale?Homework: Section Review Questions 2BPg 36, questions 1 - 4
- 42. Phase Changes ofMatterCondensation –gas to liquidVaporization – liquid to gasFreezing – liquid to solidMelting –solid to liquidSublimation – solid to gasDeposition – gas to solid