Chapter 1What Is Chemistry?§1.3 States of MatterSlide 4§1.3 Composition of Matter§1.3 Mixtures§1.4 Physical vs. Chemical Changes§1.4 Physical or Chemical Change?§1.5 Energy§1.6 SI Units of Measurement§1.6 SI Base Units§1.6 The International Prototype KilogramRed Light§1.6 SI Prefixes§1.6 SI Measurements of Time§1.6 Temperature Conversion§1.6 Kelvins§1.6 Derived Units§1.6 Volume§1.6 Density§1.7 Significant FiguresNumber Bias§1.7 Counting Significant FiguresSlide 24Slide 25Slide 26Slide 27§1.7 How many significant figures?§1.7 Addition and SubtractionSlide 30§1.7 Multiplication and Division§1.7 Combined Calculations§1.7 Accuracy vs. PrecisionSlide 34Slide 35§1.8 Dimensional Analysis§1.8 Conversion FactorsSlide 38MATTER AND MEASUREMENTChapter 1What Is Chemistry?The scientific study of matter, it properties, and interactions with other matter and with energyTherefore, the study of chemistry includes everything in the universe except for the space in a vacuum.§1.3 States of MatterMatter is anything that has mass and occupies space.Matter exists in three classical states based on whether they have a definite shape and volume.Non-classical states exist (plasma, liquid crystal, superfluids)§1.3 States of Mattersolid liquid gasDefinite shape? yes no noDefinite volume?yes yes noYesYesNoNoNoNoYesYesYesYesNoNo§1.3 Composition of MatterPure substances have constant compositions;.oElement: a substance that cannot be decomposed chemically into simpler substancesoCompound: a substance that can be broken down into elementsMixtures are impure.§1.3 MixturesHomogeneous mixtures, or solutions, have visibly indistinguishable parts.For heterogeneous mixtures, you can visually see the components, which can be separated.§1.4 Physical vs. Chemical ChangesPhysical change: a change in the form of a substance, but not its chemical composition. Chemical change: a substance becomes a new substance(s) with a different chemical composition and properties.§1.4 Physical or Chemical Change?PhysicalChemical§1.5 EnergySkip this section, we’ll cover this material in Chapter 6.§1.6 SI Units of MeasurementAll of these are based on an observable natural phenomenon except one.§1.6 SI Base Units6 out of 7 of the SI units can be measured for calibration purposes by anyone anywhere in the world. For example:o1 s = the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of 133Cso1 m = the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a secondThe kg is the only SI unit that cannot be measured.§1.6 The International Prototype KilogramThe IPK is the kilogram.Stored outside of Paris, it is taken out every 50 years.In 1992, it was revealed that the IPK had lost ~30 g (the mass of a dust particle).Red LightA typical wavelength of red light is 0.0000007 m. 0.0000007 m = 7 ⨯ 10-7 m = 700 nm§1.6 SI PrefixesPrefix SymbolDecimalEquivalentPower of 10mega- M 1,000,000 106kilo- k 1,000 103deci- d 0.1 10-1centi- c 0.01 10-2milli- m 0.001 10-3micro- 0.000 001 10-6nano- n 0.000 000 00110-9pico- p 0.000 000 000 001 10-12§1.6 SI Measurements of TimeMinutes, hours, days, etc. aren't metric, yet are still used in science.This milk is 1 year old, not 31 megaseconds.Your olfactory nerve would tell you in <1 ms not to drink this.§1.6 Temperature ConversionTK = TC + 273.15TC = TK - 273.15TF = TC(9/5) + 32TC = (TF – 32)(5/9)§1.6 KelvinsAlthough temperatures of about 0.000001 K have been reached, it is generally accepted that 0 K cannot be attained.Only use K in this class.Use of the Kelvin scale is critical for calculations that would result in division by zero or impossible results if Celsius were used.moles ideal gas = PVRT§1.6 Derived UnitsThere are 7 SI base units. All other units (derived units) are combinations of these base units.E.g., a Newton (N) is a unit of force. N = kg · m · s-2§1.6 VolumeVolume, the amount of space something occupies, is the most common derived unit. Liters are defined in terms of length:1 dm3 = 1 L = 1000 cm3 = 1000 mL1 cm3 = 1 mL2 L bottles§1.6 DensityDensity is mass per unit volume; the most common units are g/cm3.Zinc Solid 7.14§1.7 Significant FiguresA measurement always has some degree of uncertainty.Significant figures indicate precision in a measurement or experiment.Significant figures are all the certain digits and the first uncertain digit of a measurement.Number BiasAcross race, religion, culture, age and gender, human beings prefer in this order: onumbers ending in 0;onumbers ending in 5;oeven numbers.This psychological effect (number bias) can cause errors in measurement.§1.7 Counting Significant Figures1) Non-zeros are always significant.2) Zeros are sometimes significant, depending on their type. There are three types of zeros.§1.7 Counting Significant Figures2a) Leading zeros (to the left of nonzero digits) are not significant.0.210.000072 significant figures1 significant figure§1.7 Counting Significant Figures2b) Captive zeros (between nonzero digits) are always significant.10830.010.9043 significant figures4 significant figures3 significant figures§1.7 Counting Significant Figures2c) Trailing zeros (to the right of nonzero digits) are significant if the number has a decimal point.20.00020030.5 significant figures1 significant figure2 significant figures§1.7 Counting Significant Figures3) Exact numbers have no effect on the number of significant figures in a calculation.Examples of exact numbers:Counted objects (3 experiments)Defined amounts (1 km = 1000 m)Formula numbers [volume of a cone = (1/3)r2h]§1.7 How many significant figures?0.89 kg 2 1 s = 1000 ms ∞600 L 1 0.00004 kg 1108 g 3 100 atoms ∞21.03 mL 4 8.00 × 102 L 30.304 s 3 800. g 390.000 g 5  1 trillion∞ Since  is calculated, it is an inexact number. However, it is known to so many decimal places, it is like an exact number.§1.7 Addition and SubtractionThe result has the same number of decimal places as the least precise measurement used in the calculation. 19.6 + 58.33 – 4.974 = fewestdecimalplacescrudeanswerfinalanswer73.072.956§1.7 Addition and SubtractionIt’s possible to gain