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Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 1 Introduction: Matter and Measurement John D. Bookstaver St. Charles Community College St. Peters, MO 2006, Prentice Hall Matter And Measurement Matter: Anything that has mass and takes up space. Matter And Measurement Properties and Changes of Matter Matter And Measurement Properties of Matter • Physical Properties: □ Can be observed without changing a substance into another substance. • Boiling point, density, mass, volume, etc. • Chemical Properties: □ Can only be observed when a substance is changed into another substance. • Flammability, corrosiveness, reactivity with acid, etc. Matter And Measurement Properties of Matter • Intensive Properties: □ Independent of the amount of the substance that is present. • Density, boiling point, color, etc. • Extensive Properties: □ Dependent upon the amount of the substance present. • Mass, volume, energy, etc. Matter And Measurement Changes of Matter • Physical Changes: □ Changes in matter that do not change the composition of a substance. • Changes of state, temperature, volume, etc. • Chemical Changes: □ Changes that result in new substances. • Combustion, oxidation, decomposition, etc. Matter And Measurement Chemical Reactions In the course of a chemical reaction, the reacting substances are converted to new substances. Matter And Measurement Units of Measurement Matter And Measurement SI Units • There are two types of units: – fundamental (or base) units; – derived units. • There are 7 base units in the SI system. Matter And Measurement SI Units • Système International d’Unités • Uses a different base unit for each quantity Matter And Measurement Metric System Prefixes convert the base units into units that are appropriate for the item being measured. Matter And Measurement Volume • The units for volume are given by (units of length)3. – SI unit for volume is 1 m 3. • We usually use 1 mL = 1 cm3. • Other volume units: – 1 L = 1 dm3 = 1000 cm3 = 1000 mL. Matter And Measurement Uncertainty in Measurements Different measuring devices have different uses and different degrees of accuracy. Matter And Measurement Density: Physical property of a substance m d= V Matter And Measurement Do now: A graduated cylinder is filled with 15.0 mL of water. An object with a mass of 29.66 g causes the total volume to increase to 23.4 mL. What is the density of the sample? Matter And Measurement Vocabulary review • Mass : amount of matter in an object. • It is measured with a balance. • Unit in the SI system: grams g • Weight: a measure of the pull that the gravity exerts over an object. • If we stay in the same planet (same Matter And gravity) is used like the mass. Measurement Volume • The space that an object occupies. • Unit of volume in SI Liter = L Matter And Measurement What is density? • Density is a comparison of how much matter there is in a certain amount of space. • IT IS AN INTENSIVE PHYSICAL PROPERTY. It is used to identify a substance. Matter And Measurement DENSITY OF WATER • 1g/ml • That means that a gram of water has a volume of 1 milliliter or 1 cubic centimeter. Matter And Measurement Which one is more dense? • Now which one is more dense? Matter And Measurement What is density? • Density = mass volume or • mass ÷ volume. Units for density: g cm3 • Why are these the units for density? ALWAYS REMEMBER UNITS! . Matter And Measurement Let’s try a density problem together • Find the density of a yellow rock has a mass of 8 g and a volume of 4 cm3. • Use your table S to determine what element it could be! Matter And Measurement IMMISCIBLE LIQUIDS • If you pour together liquids that don’t mix and have different densities, they will form liquid layers. • Liquids that don’t mix are said to be IMMISCIBLE • The liquid with the highest density will be on the bottom. • The liquid with the lowest density will be on the top. Matter And Measurement Liquid Layers • . Which layer has the highest density? • Which layer has the lowest density? • Imagine that the liquids have the following densities: – 10g/cm3. – 6g/cm3. 3g/cm3. 5g/cm3. • Which number would go with which layer? • Is any of the liquids water? Matter And Measurement To measure the volume of an object • If is a regular object measure the dimensions needed and use the formula • cube= LxWxH • Cylinder = p h r2 • For an irregular object use the water displacement method. Matter And Measurement Liquid Layers – Try with your neighbor • Which liquid has the highest density? • Which liquid has the lowest density? • Which liquid has the middle density? Matter And Measurement Liquid Layers – Try on your own! • Imagine that the liquids on the right have the following densities: – 15g/cm3 – 3g/cm3 – 7g/cm3 10g/cm3 9g/cm3 12g/cm3 • Match the colors to the correct densities. 3g/cm3 7g/cm3 9g/cm3 10g/cm3 12g/cm3 15g/c Matter m3 And Measurement Review • What is the formula for density? • What happens if you pour together liquids that have different densities? • Will the liquid on the top have the highest or lowest density? • Will the liquid on the bottom have the highest or lowest density? Matter And Measurement Density worksheet answers • • • • • • 1=1 2=2 3=2 D of Na 0.971 g/mL 4=4 D of Mg 1.738 g/cm3 5=2 6 20g/24.4L = 0.82 g/L Matter And Measurement • HOMOGENEOUS : SAME PROPERTIES THROUGHOUT THE SAMPLE • HETEROGENEOUS : • DIFFERENT PROPERTIES IN DIFFERENT PARTS OF THE SAMPLE Matter And Measurement PURE SUBSTANCES have a constant composition • ELEMENTS – Made up of same kind of atoms. Could not be decomposed. • COMPOUNDS – Made up of different kind of atoms CHEMICALLY COMBINED. Can be decomposed. • Recognizable by formulas! Matter And Measurement Mixtures and Compounds Matter And Measurement Compounds Compounds can be broken down into more elemental particles. Matter And Measurement Matter • Atoms are the building blocks of matter. Matter And Measurement Matter • Atoms are the building blocks of matter. • Each element is made of the same kind of atom. Matter And Measurement Matter • Atoms are the building blocks of matter. • Each element is made of the same kind of atom. • A compound is made of two or more different kinds of Matter elements. And Measurement SEPTEMBER 21 • ELEMENT , COMPOUNDS AND MIXTURES • REVIEW FOR TEST • PHYSICAL AND CHEMICAL PROPERTIES • PHYSICAL AND CHEMICAL CHANGES • DENSITY Matter And Measurement MIXTURES • Combination of two or more pure substances. Can be separated by physical means. They do not have a fixed composition. • Can be homogeneous or heterogeneous. • SOLUTIONS ARE HOMOGENEOUS MIXTURES. Matter And Measurement AQUEOUS SOLUTIONS The solution is prepared using water as the solvent (aq) means DISSOLVED IN WATER!!! Na Cl (s) is a compound Na Cl (aq) is a mixture!!!! Matter And Measurement Pure Substances and Mixtures Matter And Measurement • • • • • Pure Substances and Mixtures If matter is not uniform throughout, then it is a heterogeneous mixture. If matter is uniform throughout, it is homogeneous. If homogeneous matter can be separated by physical means, then the matter is a mixture. If homogeneous matter cannot be separated by physical means, then the matter is a pure substance. If a pure substance can be decomposed into something else, then the substance is a Matter And Measurement compound. Elements • If a pure substance cannot be decomposed into something else, then the substance is an element. • There are 114 elements known. • Each element is given a unique chemical symbol (one or two letters). • Elements are building blocks of matter. • The earth’s crust consists of 5 main elements. (O, Si, Al, Fe, Ca) • The human body consists mostly of 3 main Matter And Measurement elements. (O, C, H) Elements Matter And Measurement Metals, Nonmetals, and Metalloids Matter And Measurement Symbols • First letter of element in CAPITAL letter • Second or third letter in lower case. • Some elements have symbols different from the english name • SODIUM Na • POTASSIUM K • CUPPER Cu • LEAD Pb Matter And Measurement • • • • • IRON MERCURY GOLD SILVER TIN Fe Hg Au Ag Sn Matter And Measurement Symbols from Latin Names Element Copper Gold Lead Mercury Potassium Silver Sodium Tin Symbol Cu Au Pb Hg K Ag Na Sn Latin name cuprum aurum plumbum hydrargyrum kalium argentum natrium stannum Matter And Measurement DIATOMIC ELEMENTS •H2O2F2Br2I2N2Cl2 Matter And Measurement Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement Classification of Matter Matter And Measurement MC ANSWERS • • • • • • • • • 1.A 2.A 3. A 4. D 5. A 6. B 7. C 8. D 9. D Matter And Measurement Chemical Reactions Matter And Measurement Electrolysis of Water Matter And Measurement Separation of Mixtures Matter And Measurement Distillation: Separates homogeneous mixture on the basis of differences in boiling point. Matter And Measurement Distillation Matter And Measurement Filtration: Separates solid substances from liquids and solutions. Matter And Measurement Chromatography: Separates substances on the basis of differences in solubility in a solvent. Matter And Measurement Uncertainty in Measurement Matter And Measurement Significant Figures • The term significant figures refers to digits that were measured. • When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers. Matter And Measurement • • • • Uncertainty in Measurement All scientific measures are subject to error. These errors are reflected in the number of figures reported for the measurement. Precision and Accuracy Measurements that are close to the “correct” value are accurate. Measurements that are close to each other are precise. Matter And Measurement • ACCURACY DEALS WITH THE EXACTESNESS OF THE MEASUREMENT, HOW CLOSE IT IS TO THE , TRUE, ACCEPTED OR STANDARD VALUE • PRECISSION DEALS WITH REPRODUCIBILITY OF A MEASUREMENT. • IF SEVERAL MEASUREMENTS GIVE A SIMILAR RESULT IT IS SAID THAT THE MEASUREMENT IS Matter And PRECISE Measurement Accuracy versus Precision • Accuracy refers to the proximity of a measurement to the true value of a quantity. • Precision refers to the proximity of several measurements to each other. Matter And Measurement October 5 • UNCERTAINTY IN MEASUREMENT • SIGNIFICANT FIGURES – Rules and examples • DO NOW • Calculate the density of an object that has a mass of 10.0 g and a volume of 3.0 mL. Matter And Measurement Measuring Volume by water displacement Matter And Measurement Significant Figures • The number of digits reported in a measurement reflect the accuracy of the measurement and the precision of the measuring device. • All the figures known with certainty plus one extra figure (estimated digit) are called significant figures. Matter And Measurement Sig fig in calculations • In any calculation, the results are reported to the fewest significant figures (for multiplication and division) or fewest decimal places (addition and subtraction). Matter And Measurement Significant Figures 1. All nonzero digits are significant. 2. Zeroes between two significant figures are themselves significant. 3. Zeroes at the beginning of a number are never significant. 4. Zeroes at the end of a number are significant if a decimal point is written in the number or if they are to the right Matter of a decimal point. And Measurement 0.0030 has 2 sf 400. Has 3 sf 700.00 has 5 sf Matter And Measurement EXAMPLE FOR ADDITION • Copy and perform the following operation indicating the right number of sig fig 12 1.2 0.2 --------------------Matter And Measurement MULTIPLICATION AND DIVISION 5 x 100 = 0.00022 x 745 = 3469/ 5799= Matter And Measurement Examples: How many significant figures are in each of the following? 1. 52300 m 2. 0.000487 kg 3. 29.0400 s 4. 507 people 5. 230,050 cm 6. 45.600 A Matter And Measurement Tell the number of significant digits in each of the following measurements. 1. 48 cm __________ 2. 306.2 g __________ 3. 0.329 m __________ 4. 83.9520 °C __________ 5. 3700 mm __________ 6. 400. cm3__________ 7. 71.60 g __________ 8. 0.00432 mm __________ 9. 10.0 kg __________ 10. 3.60 × 1015 sec __________ 11. 6.24 × 10-4 m __________ 12. 82.000 g __________ Matter And Measurement Tell the number of significant digits in each of the following measurements. 1. 48 cm __________ 2. 306.2 g __________ 3. 0.329 m __________ 4. 83.9520 °C __________ 5. 3700 mm __________ 6. 400. cm3__________ 7. 71.60 g __________ 8. 0.00432 mm __________ 9. 10.0 kg __________ 10. 3.60 × 1015 sec __________ 11. 6.24 × 10-4 m __________ 12. 82.000 g __________ Matter And Measurement • How do scientist express the accuracy of a measurement? • DO NOW : Observe the two instruments in my desk to measure volume, determine which would determine the volume of an Al cylinder with greater accuracy and explain in your notebook why. Matter And Measurement Percent Error • To determine the accuracy of a measurement. It tells us how far our measured stands from an accepted or known value. % error = I measured value – accepted value I X 100 ___________________________________________ accepted value Matter And Measurement Example • Calculate the percent error of the measurement for a student that determined that the density for Al is 2.5 g/mL. Hint use table T to determine the accepted value! Matter And Measurement 1) 3.482 cm + 8.51 cm + 16.324 cm ____________________ 2) 48.0032 g + 9.17 g + 65.4321 g ____________________ 3) 80.4 cm - 16.532 cm ____________________ 4) 106.5mL - 30. mL ____________________ 5) 48.2 cm × 1.6 cm × 2.12 cm ____________________ 6) 8.3 m × 4.0 m × 0.9823 m Matter And Measurement 7) 64.34 cm3 ÷ 8.149 cm ____________________ 8) 4.93 mm2 ÷ 18.71 mm ____________________ 9) 0 57 mL x 760 mm/740 mm x 273K/250 K 10) 5 13 g x 44 962amu/15 874 a m u Matter And Measurement Answers 1. 2. 3. 4. 5. 6. 7. 8. 28.32 cm 122.61 g 63.9 cm 76 mL 160 cm3 33 m3 7.895 cm2 0.263 mm Matter And Measurement MULTIPLE CHOICE 1. 2. 3. 4. 5. 6. 7. 8. 3 2 3 2 1 1 4 1 Matter And Measurement • 1. According to an accepted chemistry reference. the heat of vaporization of water is 540. calories per gram. A student determined in the laboratory that the heat of vaporization of water was 620. calories per gram. The student's results had a percent error of (1) 12.9, (2) 80.0, (3) 14.8, (4) 87.1 • 2. Which measurement contains a total of three significant figures? • (1) 0.01 g (2) 0.0100 g (3) 0.010 g (4) Matter And 0.01000 g Measurement 3. In an experiment the gram atomic mass of magnesium was determined to be 24.7. Compared to the accepted value 24.3, the percent error for this determination was (1) 0. 400, (2) 24.7, (3) 1.65, (4) 98.4 4. A student determined the melting point of a substance to be 55.2°C. If the accepted value is 50. 1°C the percent error in her determination is (1) 5.10, (2) 10.2, (3) 9.24, (4) 12.0 5. Using the rules for significant figures, the sum of 0. 027 gram and 0. 0023 gram should be expressed as (1) 0. 029 gram, (2) 0.03 gram, (3) 0.0293 gram, (4) 0.030 gram Matter And Measurement 6. Which milligram quantity contains a total of four significant figures? (1) 0.3010 mg (2) 3100 mg (2) 3010 mg (4) 30001 mg Matter And Measurement Scientific Notation •Numbers written in scientific notation include a numeral with one digit before the decimal point, multiplied by some power of ten (6.022 x 1023) •In scientific notation, all digits are significant. •You should be able to convert from non-scientific notation to scientific and vice-versa. Matter And Measurement • • • • Temperature Definition Instrument Scales Matter And Measurement TEMPERATURE • Is associated with heat but it is NOT HEAT. IT IS NOT A FORM OF ENERGY!!!! ( Heat is) • Review: What is KINETIC ENERGY? Matter And Measurement KINETIC ENERGY (KE) • Is associated with movement. • If an object is moving fast has high KE • If an object is moving slowly it has low KE Matter And Measurement Temperature • In scientific measurements, the Celsius and Kelvin scales are most often used. • The Celsius scale is based on the properties of water. □ 0C is the freezing point of water. □ 100C is the boiling point of water. Matter And Measurement Temperature: A measure of the average kinetic energy of the particles in a sample. If an object is at HIGH temperature its particles are moving FAST At LOW temperature particles move SLOWLY Matter And Measurement Instrument to measure temperature THERMOMETER Matter And Measurement FIXED POINTS OF A THERMOMETER • BOILING POINT OF WATER • FREEZING POINT OF WATER Matter And Measurement Temperature • The Kelvin is the SI unit of temperature. • It is based on the properties of gases. • There are no negative Kelvin temperatures. • K = C + 273.15 Matter And Measurement Temperature • The Fahrenheit scale is not used in scientific measurements. • F = 9/5(C) + 32 • C = 5/9(F − 32) Matter And Measurement Examples: 1. What is 35ºC in Kelvin? In ºF? 2. What is 183 K in ºC? In ºF? Matter And Measurement