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BIO. Medicine. Physics. CHEM. Engr. GEO. Law. Matter. What is Chemistry Study of the “Physical” Properties Matter (Form and Function) Study of How Matter Changes (Reactivity) Benefits of Chemistry Pharmaceuticals Enhanced food production (fertilizers, herbicides, etc...)
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BIO Medicine Physics CHEM Engr GEO Law Matter • What is Chemistry • Study of the “Physical” Properties Matter (Form and Function) • Study of How Matter Changes (Reactivity) • Benefits of Chemistry • Pharmaceuticals • Enhanced food production (fertilizers, herbicides, etc...) • Plastics and Polymers • Why Study Chemistry • Core requirement (?) • Central Science • Employment • Many fields also: environmental economics electronics agriculture politics etc... S.U. B.S. Chapt. 1.1
Matter; A Review • Definition of Matter • anything that occupies space and has mass • States • gas (vapor); no fixed volume or shape, compressable • liquid; fixed volume no fixed shape, mostly incompressable • solid; fixed volume and shape, incompressable • Forms • Substances (pure or single); has a fixed composition and distinct properties. Most things encountered are mixtures of substances. • Properties • Physical Properties; can be measured without changing the substance, i.e., color, density, melting point, etc... • Chemical Properties; the way a substance changes (reacts), i.e., combustion Chapt. 1.1
Matter; A Review • Changes • Physical - Changes in appearance but not identity, i.e., evaporation, melting (all changes of state) • Chemical - transformation into a different substance Chemical Changes Physical Changes burning melting C6H12O6 + 6O2 6CO2 + 6H2O H2O(s) H2O(l) chemical reactions sublimation NaOH + HCl H2O + NaCl H2O(s) H2O(g) corrosion dissolution 4Fe + 3O2 2 Fe2O3 H2O(l ) + NaCl(s) NaCl(aq) Chapt. 1.1
Matter; A Review • Mixtures; combinations of substances • Mixture- • Homogeneous – • Heterogeneous - Chapt. 1.1
Filter Matter; A Review • Filtration • Sand from Salt • Separating Mixtures using Physical Properties • How would you separate; Flow Everyday Examples; Auto Oil Filter Auto Air Filter Aquarium Water Filter Spaghetti Strainer Window Screens Registrar Chapt. 1.1
Matter; A Review • Distillation • Water from Salt Water • Separating Mixtures using Physical Properties • How would you separate; NaCl(s) + H2O(l) NaCl(aq) Chapt. 1.1
Matter; A Review • Chromatograpgy • Dyes from M&M’s • Separating Mixtures using Physical Properties • How would you separate; Before After Dyes Chapt. 1.1
Matter; A Review • Salt and Sand Mixture Ink from Cabbage Juice • solubility and filtration chromatography • Water from Salt Water Iron and Gold Mixture • distillation magnetic properties • melting point differences • chem. reactivity (acids) • Iodine from Copper Chloride • solubility and filtration • Separating Mixtures using Physical Properties • How would you separate; Chapt. 1.1
Matter; Elements and Compounds • Substances • Elements - substances which cannot be decomposed into simpler substances (see periodic table) • Compounds- substances which can be separated into two or more elements • Elements • 110 Known (periodic table to be revisited) • make up all matter and composed of “subatomic particles” • symbols used for abbreviations (from older or common names) • Compounds • Elements combined in a definite proportion by mass (law of definite proportion) • properties different than consititutent elements Water; example of mixtures, compound and elements? Chapt. 1.2
Matter Matter No Yes Uniform ? Heterogeneous Mixture Homogeneous Can be separated by physical methods No Pure Substance Yes Decomposed ? Homogeneous Mixture (solution) No Yes Element Compound
Matter; Measurement • Systems • Metric - base 10 • SI- international scientific system • mass Kilogram • length Meter • time Second • electric current Ampere • temperature Kelvin • light Candela • Amount Mole • Factor label method for conversions Chapt. 1.3
Matter; Measurement • Prefixes Mega M 106 Kilo k 103 Deci d 10-1 Centi c 10-2 Milli m 10-3 Micro 10-6 Nano n 10-9 Chapt. 1.3
Matter; Measurement Common Units: • Length and Mass • Length - unit of distance measured in meters • Mass - measures the amount of matter in an object in grams • Temperature • Kelvin • Celsius °C = 5/9 (°F -32) K = °C + 273.15 Chapt. 1.3
Matter; Measurement Sample exercise: Ethylene glycol, the major ingredient in antifreeze, freezes at -11.5°C. What is the freezing point in a) K b) °F Chapt. 1.3
Matter; Measurement Derived Units: • Volume • Length x length x length • measured in cm3, which is equal to mL Chapt. 1.3
Matter; Measurement Derived Units: • Density • amount of mass per unit volume • measured in g/cm3, or g/mL Chapt. 1.3
Matter; Measurement Sample exercise: A student needs 15.0 g of ethanol (ethyl alcohol) for an experiment. If the density of the alcohol is 0.789 g/mL, how many milliliters of alcohol are needed? Chapt. 1.3
Matter; Uncertainty in Measurement • Precision and Accuracy • Precision - how closely individual measurements agree • Accuracy- how closely the measurements agree with the true value • Significant Figures • All measurements are inaccurate intrinsically • measured quantities are reported such that the last figure is uncertain Chapt. 1.4
Matter; Uncertainty in Measurement Good Precision Poor Accuracy Good Precision Good Accuracy Poor Precision Poor Accuracy
Matter; Uncertainty in Measurement • Determining Significant Figures • all non zero digits are significant • zeros between nonzero digits are significant • zeros to the left of first nonzero digit are not significant • zeros at the end of a number and to the right of a decimal point are significant • when a number ends in a zero but with no decimal point, the zero may or may not be signigicant (use scientific notation) Chapt. 1.4
Matter; Uncertainty in Measurement • Determining Significant Figures 3.573 has 4 significant figures 0.073 has 2 significant figures 3.070 has 4 significant figures 0.003 has 1 significant figures - multiplication and division; result can have no more than the figure with the fewest significant figures - addition and subtraction; result can have the same number of decimal places as the term with the least number of decimal places Chapt. 1.4
Matter; Uncertainty in Measurement Sample exercise: How many significant figures are in each of the following measurements? A) 3.549 g B) 2.3 x 104 cm C) 0.00134 m3 Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: How many significant figures are in each of the following measurements? A) 3.549 g 4 sig figs B) 2.3 x 104 cm C) 0.00134 m3 Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: How many significant figures are in each of the following measurements? A) 3.549 g 4 sig figs B) 2.3 x 104 cm 2 sig figs C) 0.00134 m3 Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: How many significant figures are in each of the following measurements? A) 3.549 g 4 sig figs B) 2.3 x 104 cm 2 sig figs C) 0.00134 m3 3 sig figs Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: There are exactly 1609.344 m in a mile. How many meters are in a distance of 1.35 mi? Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: There are exactly 1609.344 m in a mile. How many meters are in a distance of 1.35 mi? 1.35 mi = 1 mi x 1609.344 m Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: There are exactly 1609.344 m in a mile. How many meters are in a distance of 1.35 mi? 1.35 mi = 1 mi x 1609.344 m x = 2172.6144 m Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: There are exactly 1609.344 m in a mile. How many meters are in a distance of 1.35 mi? 1.35 mi = 1 mi x 1609.344 m 1.35 has 3 sig figs x = 2172.6144 m 1609.344 has 7 sig figs 1 is infinitely significant Chapt. 1.3
Matter; Uncertainty in Measurement Sample exercise: There are exactly 1609.344 m in a mile. How many meters are in a distance of 1.35 mi? 1.35 mi = 1 mi x 1609.344 m 1.35 has 3 sig figs x = 2172.6144 m 1609.344 has 7 sig figs x = 2170 m 1 is infinitely significant Chapt. 1.3
Dimensional Analysis • Use Units throughout the calculation (helps “guide” calculation. • Should always yield the proper units • Uses conversion factors • Example; How fast is 50 mph in in/sec.? 50 mi. 1 hour 5280 ft 12 in. = in 1 hour 3600 sec. 1 mi. 1 ft sec.
Dimensional Analysis Sample exercise: By using a conversion factor from the back inside cover, determine the length in kilometers of a 500.0 mi automobile race. Chapt. 1.3
Dimensional Analysis Sample exercise: By using a conversion factor from the back inside cover, determine the length in kilometers of a 500.0 mi automobile race. 500.0 mi Chapt. 1.3
Dimensional Analysis Sample exercise: By using a conversion factor from the back inside cover, determine the length in kilometers of a 500.0 mi automobile race. 500.0 mi 1 km 0.62137 mi Chapt. 1.3
Dimensional Analysis Sample exercise: By using a conversion factor from the back inside cover, determine the length in kilometers of a 500.0 mi automobile race. 500.0 mi 1 km = 804.674 km 0.62137 mi Chapt. 1.3
Dimensional Analysis Sample exercise: By using a conversion factor from the back inside cover, determine the length in kilometers of a 500.0 mi automobile race. 500.0 mi 1 km = 804.674 km 0.62137 mi * answer can only have 4 sig figs; 804.7 km Chapt. 1.3
Chapter One; Review • Matter: Chemical and Physical Changes • Elements and Compounds • Units of Measurement • Uncertainty and Significant Figures • Precision and Accuracy • “Factor Label” Method (Dimensional Analysis)