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Chapter Chapter One Scientific Measurements Practice Exercises 1.1 The scientific method is an iterative process of gathering information through making observations and collecting data and then formulating explanations that lead to a conclusion 1.2 (a) element (d) mixture, heterogeneous (b) mixture, homogeneous (e) element 1.3 (a) chemical change (c) physical change (b) physical change (d) physical change 1.4 (a) intensive (c) intensive (b) extensive (d) extensive 1.5 V= (c) compound 4 pr , the SI unit for radius, r, is meters, the numbers and not have units Therefore, 3 the SI unit for volume is meter3 or m3 1.6 Force equals mass × acceleration (F = ma), and acceleration equals change in velocity divided by change in time (a = d change in v ), and velocity equals distance divided by time (v = ) Put the t change in t equations together: æ change in v ÷ è change in t ø ổ dử ổ ỗ change in ữ t ữ = m ỗ change in d ữ F= m ỗ ç 2÷ ç change in t ÷ è change in t ứ ỗ ữ ố ứ F = mỗ The unit for mass is kilogram (kg); the unit for distance is meter (m) and the unit for time is second (s) Substitute the units into the equation above: ỉmư ÷ or kg m s–2 è s2 ø Unit for force in SI base units = kg ỗ 1.7 ổ F ổ F tF = ỗ t + 32 F = ỗ 355 C + 32 F =671 °F è °C ÷ø C è °C ÷ø 1.8 ỉ °C ỉ °C tC = tF - 32 F ỗ = 55 o F - 32 F ỗ = 13 C ữ ố °F ø è °F ÷ø ( ( ) ( ) ) To convert from °F to K we first convert to °C ỉ °C ỉ C tC = tF - 32 F ỗ = 68 F - 32 F ỗ = 20 C ữ è °F ø è °F ÷ø ỉ1K ổ1K TK = (273 C + tC) ỗ ữ = (273 C + 20 C) ỗ ữ = 293 K è °C ø è °C ø ( 1.9 (a) (b) ) ( ) 21.0233 g + 21.0 g = 42.0233 g: rounded correctly to 42.0 g 10.0324 g / 11.7 mL = 0.8574 g / mL: rounded correctly to 0.857 g/mL 1-1 Chapter 1.10 (c) 14.25 cm ´ 12.334 cm = 148.57 cm: rounded correctly to 149 cm 2.223 cm - 1.04 cm (a) (b) 54.183 g – 0.0278 g = 54.155 g 10.0 g + 1.03 g + 0.243 g = 11.3 g (rounded after adding) (c) 43.4 in ì ỗ (d) 1.03 m 2.074 m ´ 2.9 m = 0.36 m2 12.46 m + 4.778 m ( ) ỉ ft ÷ = 3.62 ft (1 and 12 are exact numbers) è 12 in ø ( ) 1.11 ỉ 30.48 cm ư2 æ m ö2 m2 = 124 ft ç ÷ ç ÷ = 11.5 m è ft ø è 100 cm ø 1.12 (a) (b) (c) (d) ( ) ỉ ft ư3 ỉ 12 in ư3 in = 3.00 yd ỗ ữ ỗ ÷ = 140,000 in = 1.40 ´ 10 in è yd ø è ft ø æ 1000 m ửổ 100 cm cm = 1.25 km ỗ ữỗ ữ = 1.25 10 cm ố km øè m ø ỉ 28.35 g g = 3.27 oz ỗ ữ = 92.7 g ố oz ø km ỉ 20.2 mile ưỉ 1.609 km ưỉ gal =ỗ ữỗ ữỗ ữ = 8.59 km L L è gal øè mile øè 3.785 L ø 3 ( ( ) ) 1.13 Density = mass 0.244 g = = 0.0163 g/mL = 0.0163 g cm–3 volume 15.0 mL 1.14 Density = mass mass 0.547 g = = =2.2 g mL–1 = 2.2 g cm–3 volume V f -Vi (5.95 mL – 5.70 mL) 1.15 Density = mass volume Density of the object = 365 g = 16.5 g/cm3 22.12 cm The object is not composed of pure gold since the density of gold is 19.3 g/cm3 1.16 The density of the alloy is 12.6 g/cm3 To determine the mass of the 0.822 ft3 sample of the alloy, first convert the density from g/cm3 to lb/ft3, then find the weight Density in lb/ft3 = 12.6 g ỉ lb ưỉ 30.48 cm ç ÷ç ÷ = 787 lb/ft3 cm3 è 453.6 g øè ft ø Mass of sample alloy = (0.822 ft3) (787 lb/ft3) = 647 lb 1.17 density of substance density of water density of wine specific gravity = 1.090 = 62.4 lb ft density of wine = 1.090 62.4 lb ft3 = 68.02 lb ft3 1-2 Chapter mass of wine = 79 gallons density of wine = 79 gallons 1.18 68.02 lb ft ´ ft 7.481 gallons ft = 720 lb 7.481 gallons density of substance density of water 1.00 g ỉ oz ưỉ 29.574 mL density of water = ỗ ữỗ ữ = 1.043 oz/liquid oz mL è 28.3495 g øè liquid oz ø 1.008 oz/liquid oz specific gravity of urine = = 0.966 1.043 oz/liquid oz specific gravity = The specific gravity of urine is below the normal range Review Questions 1.1 This answer will be student dependent 1.2 Observation, testing and explanation 1.3 (a) (b) (c) A law is a description of behavior based on the results of many experiments which are true while a theory is a tested explanation of the results of many experiments An observation is a statement that accurately describes something we see, hear, taste, feel or smell while a conclusion is a statement that is based on a series of observations Data are the observations made while performing experiments 1.4 A theory is valid as long as there is no experimental evidence to disprove it Any experimental evidence that contradicts the theory, and therefore, disproves the theory 1.5 Matter has mass and occupies space All items, except (b) an idea, in the question are examples of matter 1.6 (a) (b) (c) (d) (e) (f) (g) An element is a pure substance that cannot be decomposed into something simpler A compound is a pure substance that is composed of two or more elements in some fixed or characteristic proportion Mixtures result from combinations of pure substances in varying proportions A homogeneous mixture has one phase It has the same properties throughout the sample A heterogeneous mixture has more than one phase The different phases have different properties A phase is a region of a mixture that has properties that are different from other regions of the mixture A solution is a homogeneous mixture 1.7 Changing a compound into its element is a chemical change 1.8 (a) (e) (i) F Li Hg (b) (f) (j) Se P Mn (c) (g) 1-3 Ni I (d) (h) Ar Ga Chapter 1.9 (a) (d) (g) (j) sodium tin cobalt nitrogen 1.10 (a) (b) (c) (d) This is a heterogeneous mixture This is a pure substance and is an element, such as H2, O2, N2 or a halogen This is a homogeneous mixture This is a pure substance and is a molecule such as H2O 1.11 (a) (b) (c) Diagrams (a) and (d) contain pure elements Diagram (c) contains a compound Diagram (a) and (b) contain diatomic molecules 1.12 A physical change does not change the chemical composition of matter Melting, boiling, change of shape, or mass, and the formation of a mixture are examples of physical changes to matter A chemical change changes the chemical composition of matter Formation of new compounds from the reaction of other substances is an example A chemical changes involves the change in composition while a physical change does not change in the composition of matter 1.13 The reaction of calcium metal with water is a chemical change resulting in the formation of new compounds, hydrogen gas and calcium hydroxide It is not stated in the problem, but the water also increases in temperature, which is a physical change 1.14 These are all physical changes 1.15 A chemical property describes a property that changes the chemical nature of a substance while physical properties describe properties that not change the chemical nature of a substance For example, boiling water does not change the chemical composition of water 1.16 Extensive properties, such as volume, and size, are properties that depend on the amount of substance or mass of substance while intensive properties, such as density, are not dependent on the amount of substance The density of a milliliter of water is the same as the density of a liter of water at the same temperature 1.17 (a) (b) (c) (d) (e) (f) (g) (b) (e) (h) zinc magnesium aluminum (c) (f) (i) silicon tungsten oxygen Extensive Mass is a mass dependent property Intensive The boiling point of a substance is the same for a mL as it is for a L of the compound so it is mass independent Intensive The color of a substance does not change when you change the amount of substance Extensive Surface area depends on the amount of substance It also depends on the nature of the substance A bar of metal has a smaller surface area than that of the same bar ground into fine particles Intensive The physical state, gas, liquid, or solid, depends on temperature and pressure but not on the mass of the substance Intensive The density of 1.0 g of water is the same as 100.0 g if both samples are at the same temperature Thus, density is not dependent on the mass of substance Extensive The volume occupied by a substance is dependent on the mass of substance 1-4 Chapter 1.18 (a) (b) (c) Gas Liquid Solid Temperature, density, volume, viscosity Temperature, density, volume, viscosity Temperature, density, volume 1.19 Measurements involve a comparison The unit gives the number meaning 1.20 Kilogram 1.21 Kilogram, meter, second, kelvin 1.22 Derived units are a result of multiplying or dividing a unit by 1, by a multiplier, or by another unit Examples include m2 for area, m/s for velocity, kg m/s2 for energy 1.23 (a) (b) (c) (d) (e) (f) (g) 1.24 The melting points and boiling points of water at atmosphere pressure On the Celsius scale these points correspond to °C and 100 °C respectively 1.25 (a) Fahrenheit degree < Celsius degree (b) Celsius degree = Kelvin (c) Fahrenheit degree < Kelvin 1.26 The digits that are significant figures in a quantity are those that are known (measured) with certainty plus the last digit, which contains some uncertainty 1.27 Rounding numbers: if the number after the significant figure is less than 5, keep the number If the number after the significant figure is or more, and if it is and the is followed by nonzero digits, raise the number by If the number after the significant figure is 5, and followed by a zero, drop the if the preceding digit is even, add if it is odd 1.28 The accuracy of a measured value is the closeness of that value to the true value of the quantity The precision of a number of repeated measurements of the same quantity is the closeness of the measurements to one another 1.29 The minimum uncertainty that is implied in this measurement is ± 0.01 cm 1.30 In addition, the significant figures are the least precise number In multiplication, the number of significant figures in the answer depends on smallest number of significant figures 1.31 The unit that you start with is the denominator and the desired unit is the numerator 1.32 The problem with using the fraction yd/1 ft as a conversion factor is that there are feet in one yard The conversion factor should be yd/3 ft For the second part of the question, it is not possible to construct a valid conversion factor relating centimeters to meters from the equation cm = 1000 m, since 100 cm = m 0.01 0.001 1000 0.000001 0.000000001 0.000000000001 1,000,000 10–2 10–3 103 10–6 10–9 10–12 106 c m k (the Greek letter mu) n p M 1-5 Chapter 1.33 To convert 250 seconds to hours multiply 250 by: 1h 3600 s To convert 3.84 hours to seconds multiply 3.84 hours by: 3600 s 1h 1.34 Four significant figures would be correct because the conversion factor contains exact values The measured value determines the number of significant figures 1.35 d= 1.36 Density is the ratio of the mass of a substance divided by its volume and is an intensive property Specific gravity is the ratio of the density of a substance divided by the density of water using the same units Specific gravity does not have any units Specific gravity is useful since it avoids units, and only the density of water with the desired units needs to be tabulated 1.37 The answer will be student dependent, but some answers might be g/mL, lb/ gallon, kg/L, ft 3/lb These would have to be divided by the density of water with the same units: 1.00 g/mL, 8.34 lb/gallon, 1.00 kg/L, 62.4 lb/ft3 at 25 °C 1.38 10.5 g silver = cm3 silver m : d = density; m = mass; V = volume V 10.5 g Ag cm3 and cm3 10.5 g Ag Review Problems 1.39 (a) (b) (c) (d) (e) 1.40 (a) (b) (c) (d) (e) 1.41 (a) (b) (c) Physical change Copper does not change chemically when electricity flows through it: It remains copper Physical change Gallium is changes its state, not its chemical composition when it melts Chemical change This is an example of the Maillard reaction describing the chemical reaction of sugar molecules and amino acids Chemical change Wine contains ethanol which can be converted to acetic acid Chemical change Concrete is composed of many different substances that undergo a chemical process called hydration when water is added to it Chemical change Iron reacts with oxygen to form the rust Physical change When corn is popped water is turned into steam by heating the corn The pressure of the steam caused the kernel to pop open resulting in popped corn Physical change Generally alloys are mixtures of substances and no chemical change occurs On occasion, a chemical change can occur during the production of an alloy Physical change During the production of butter fat molecules aggregate, due to the agitation of whipping, and separate from the water Physical change The water vapor becomes the liquid and does not change its chemical composition Hydrogen is a gas at room temperature Aluminum is a solid at room temperature Nitrogen is a gas at room temperature 1-6 Chapter (d) Mercury is a liquid at room temperature 1.42 (a) (b) (c) (d) Potassium chloride is a solid at room temperature Carbon dioxide is a gas at room temperature Methane is a gas at room temperature Sucrose is a solid at room temperature 1.43 (a) 0.01 (b) 1000 (c) 1012 (d) 0.1 (e) 0.001 (f) (b) (e) 10–6 10–3 (c) (f) 103 0.1 1.44 (a) (d) 10–9 106 1.45 (a) tF = ỗ 0.01 ổ F ổ F ữ (tC) + 32 F = ỗ ữ (57 °C) + 32 °F = 135 F when rounded to the proper è °C ø è °C ø number of significant figures ỉ °C ỉ C ữ (tF 32 F) = ỗ ÷ (–25.5 °F – 32 °F) = –31.9 C è °F ø è °F ø æ °C ö æ °C ö tC = (TK – 273 K) ỗ ữ = (378 K 273 K) ỗ ÷ = 105 C è1K ø è1K ø ỉ1K ổ1K TK = (tC + 273 C) ỗ ữ = (31 + 273) ỗ ữ = 242 K ố C ứ ố C ứ tC = ỗ (b) (c) (d) 1.46 ỉ °C ỉ C ữ (tF 32 F) = ỗ ữ (98 °F – 32 °F) = 37 C è °F ø è °F ø ỉ °F ổ F tF = ỗ ữ (tC) + 32 F = ỗ ữ (55 C) +32 F = –67 F è °C ø è °C ø æ °C ö æ °C ö tC = (TK 273 K) ỗ ữ = (299 K 273 K) ỗ ữ = 26 C ố1K ứ ố1K ø ỉ1K ỉ1K TK = (tC + 273 C) ỗ ữ = (40 C + 273 C) ỗ ÷ = 313 K è °C ø è C ứ tC = ỗ (a) (b) (c) (d) 1.47 Temperature in °C: ỉ °C ỉ °C ữ = (15.7 ì 106 K 273 K) ỗ ữ = 15.7 ì 106 C ố1K ứ ố1K ứ tC = (TK 273 K) ỗ Temperature in °F: ỉ °F ỉ °F ÷ (C) + 32 F = ỗ ữ (15.7 ì 106 C) + 32 °F = 2.83 × 107 F è C ứ ố C ứ tF = ỗ 1.48 Temperature in °C: ỉ °C ỉ C ữ = (109 K 273 K) ỗ ÷ = –164 C è1K ø è1K ø tC = (TK 273 K) ỗ Temperature in F: ổ °F ÷ (C) + 32 °F = è C ứ tF = ỗ ổ F ỗ ÷ (–164 C) + 32 °F = –263.2 F è °C ø 1-7 Chapter 1.49 æ °C o tC = ( tF - 32 F) ỗ ÷ = 103.5 F - 32 °F è °F ứ ( ổ )ỗố 59 CF ữứ = 39.7 °C This dog has a fever; the temperature above is out of normal canine range 1.50 ỉ °C o tC = ( tF - 32 F) ỗ ữ = 120.0 F - 32 °F °F è ø ( ổ )ỗố 59 CF ữứ = 48.89 C The temperature in Death Valley, 56.7 °C, was warmer 1.51 9.2 cm, significant figures; 9.15 cm, significant figures 1.52 24.25 °C, significant figures; 18.9 °C, significant figures 1.53 (a) (c) (e) significant figures significant figures significant figures (b) (d) significant figures significant figures 1.54 (a) (c) (e) significant figures significant figures significant figure (b) (d) significant figures significant figures 1.55 (a) (c) (d) 0.72 m2 (b) 84.24 kg 4.19 g/cm (dividing a number with sig figs by one with sig figs) 19.42 g/mL (e) 858.0 cm2 1.56 (a) (c) (e) 2.06 g/mL 12.4 g/mL 0.0006 m/s2 1.57 (a) (b) (c) (d) finite number of significant figures exact number finite number of significant figures finite number of significant figures 1.58 (a) (b) (c) (d) finite number of significant figures finite number of significant figures finite number of significant figures exact number 1.59 (a) (b) (c) (d) (e) (b) (d) 4.02 mL 0.276 g/mL æ m ưỉ km ưỉ 3600 s km/hr = 32.0 dm/s ỗ ữỗ ữỗ ữ = 11.5 km/h è 10 dm øè 1000 m øè h ø æ g öæ ´ 106 mg öæ 1000 mL ữỗ mg/L = 8.2 mg/mL ỗ = 8.2 106 mg/L ữỗ ữố L ữứ 1g ố 1000 mg ứỗố ứ ổ g ửổ kg -5 kg = 75.3 mg ỗ ữỗ ữ = 7.53 ´ 10 kg è 1000 mg øè 1000 g ứ ổ 1L L = 137.5 mL ỗ ữ = 0.1375 L è 1000 mL ø æ 1000 mL mL = 0.025 L ỗ ữ = 25 mL è 1L ø ( ) ( ( ) ) ( ) ( ) 1-8 Chapter 1.60 (f) æ ử2 110-12 m ữ ổ 10 dm ỗ dm = 342 pm = 3.42 10-20 dm ỗ pm ữ ỗố m ữứ ố ứ (a) æ L öæ 1000 cm3 öæ m ö3 ổ 106 mm ỗ ữ ỗ ữ m = (92 dL) ỗ = 9.2 ì 1015 m3 ữ ỗ ữ ố 10 dL ứỗố L ữứố 100 cm ứ ỗố m ữứ (b) g = (22 ng) çç (c) nL = (83 pL) çç (d) m3 = (230 km3) ỗ (e) km hr-2 = (87.3 cm s2) ç (f) nm2 = (238 mm2) ç ( ỉ g ưỉ 106 mg ÷ = 0.022 g ữỗ ữỗ ữ ố 10 ng ứố g ø æ 1.61 (a) (b) (c) (d) (e) (f) 1.62 (a) (b) (c) (d) (e) ) ưỉ 109 nL ữ ữỗ ữỗ L ữ = 0.083 nL pL øè ø 1L 12 è 10 æ 1000 m ử3 ữ = 2.3 ì 1011 m3 ố km ø ỉ m ưỉ km ưỉ 3600 s ử2 ữỗ ữỗ ữ = 1.13 ì 104 km hr-2 è 100 cm øè 1000 m øè hr ø 2 m ỉ nm ÷ = 2.38 ì 1014 nm2 ữ ỗ ố 1000 mm ø è 10-9 m ø ỉ ỉ 2.54 cm cm = 36 in ỗ ữ = 91 cm ố in ø ỉ kg kg = 5.0 lb ỗ ữ = 2.3 kg ố 2.205 lb ứ ổ 946.4 mL mL = 3.0 qt ỗ ữ = 2800 mL è qt ø æ 29.6 mL mL = oz ỗ ữ = 200 mL è oz ø ỉ 1.609 km km/hr = 55 mi/hr ỗ ữ = 88 km/hr ố mi ứ ổ 1.609 km km = 50.0 mi ỗ ÷ = 80.4 km è mi ø ( ) ( ) ( ) ( ) ( ) ( ) ổ qt qt = 250 mL ỗ ữ = 0.26 qt è 946.4 mL ø æ 12 in öæ 2.54 cm öæ m ö m = 3.0 ft ỗ ữỗ ữỗ ữ = 0.91 m ố ft øè in øè 100 cm ø æ 2.205 lb lb = 1.62 kg ỗ ữ = 3.57 lb è kg ø ỉ 1000 mL ưỉ oz oz = 1.75 L ỗ ữỗ ữ = 59.1 oz è L øè 29.6 mL ø æ mi mi/hr = 35 km/hr ỗ ữ = 22 mi/hr è 1.609 km ø ( ) ( ) ( ) ( ) ( ) 1-9 Chapter æ mi mi = 80.0 km ỗ ữ = 49.7 mi è 1.609 km ø ( (f) 1.63 1.64 1.65 ) ( ) ỉ 30.48 cm ư2 = 8.4 ft ỗ ữ = 7,800 cm ố ft ø 2 (a) cm (b) ỉ 1.609 km ư2 km = 223 mi ỗ ữ = 577 km è mi ø (c) æ 30.48 cm ử3 cm3 = 231 ft ỗ ữ = 6.54 ´10 cm è ft ø (a) æ 0.9144 m ử2 m = (2.4 yd ) ỗ ữ = 2.0 m2 è yd ø (b) mm2 = (8.3 in2) ỗ (c) L = (9.1 ft3) ỗ ( ) ( ) 2 ỉ 2.54 cm ư2 ỉ 10 mm ử2 ữ ỗ ữ = 5400 mm2 ố in ø è cm ø æ yd ö3 æ 0.9144 m ö3 æ 100 cm ö3 æ mL ửổ L ữỗ ữ ỗ ữ ç ÷ ç ÷ = 260 L è 3ft ø è yd ø è m ø è cm3 øè 1000 mL ø ỉ 946.35 mL mL = 4.2 qt ỗ ữ = 4.0 10 mL (stomach volume) è qt ø ( ) 4.0 × 103 mL 0.9 mL = 4,000 pistachios (don’t try this at home) 1.66 To determine if 50 eggs will fit into 4.2 quarts, calculate the volume of fifty eggs, then compare the answer to the volume of the stomach: ỉ 53 mL ưỉ L ưỉ 1.057 qt ữỗ ữỗ ữ = 2.8 qt ố egg øè 1000 mL øè L ø Volume of 50 eggs = (50 eggs) ỗ 2.8 qt < 4.2 qt Luke can eat 50 eggs 1.67 ỉ 200 mi æ 5280 ft ö æ 30.48 cm ö æ 1´10-2m ö æ hr ö æ ö m m = ỗ = 89.4 ỗ ữỗ ữ ỗ ữ ç ÷ ÷ ç ÷ s s è hr ø è mi ø è ft ø è cm ø è 60 ø è 60 s ứ 1.68 km/h = ỗ 1.69 ổ 2230 ft ửổ mi ưỉ 60 s ưỉ 60 mi mi = ỗ ữỗ ữỗ ữỗ ữ = 1520 hr hr è s øè 5280 ft øè øè hr ø 1.70 tons/day = 2.05´105 1.71 light year = y ỗ ổ 2435 ft ửổ yd ưỉ 0.9144 m ưỉ km ưỉ 3600 s ữỗ ữỗ ữỗ ữỗ ữ = 2672 km/h è s øè ft øè yd øè 1000 m øè h ø ft æ 62.4 lb öæ ton öæ 3600 s öæ 24 h ö ỗ ữỗ ữỗ ữỗ ữ = 5.53 ì 108 tons/day s è ft øè 2000 lb øè h øè d ø ỉ 365.25 d ưỉ 24 h ưỉ 3600 s ưỉ 3.00 ´108 m ÷ = 9.47 ì 1015 m ữỗ ữỗ ữỗ ữ 1s ố y ứố d ứố h ứỗố ø 1-10 Chapter ỉ 9.47 ´ 1015m ÷ỉ km ưỉ mi = 5.1 × 1013 mi ỗ light year ữỗố 1000 m ữứỗố 1.609 km ữứ ố ứ miles = 8.7 light years ỗ 1.72 There are 360 degrees of latitude around the circumference of the earth ỉ 60 nautical miles ưỉ 1.151 statute miles ữỗ ữ ố degree latitude ứố nautical mile ứ statute miles = 360 degree latitude ỗ = 2.49 × 104 statute miles 1.73 density = mass/ volume = 36.4 g/45.6 mL = 0.798 g/mL 1.74 density = mass volume d= 14.3 g 8.46 cm = 1.69 g/cm3 1.75 ỉ mL mL = 25.0 g ỗ ữ = 31.6 mL ố 0.791 g ứ 1.76 mL = ( 26.223 g) ỗ 1.77 ổ 1.492 g g = 185 mL ỗ ữ = 276 g è mL ø 1.78 ỉ 1000 mL æ 0.65 g ö æ kg ö kg = 34 L ỗ = 22.1 kg ố L ữứ çè mL ÷ø çè 1000 g ÷ø ỉ mL ÷ = 26.301 mL è 0.99704 g ø ( ) ỉ 2.2 lbs lbs = 22.1 kg ç = 49 lbs è kg ÷ø ( ) 1.79 mass of silver = 62.00 g – 27.35 g = 34.65 g volume of silver = 18.3 mL –15 mL = 3.3 mL or 3.3 cm3 density of silver = (mass of silver)/(volume of silver) = (34.65 g)/(3.3 cm3) = 11 g/cm3 1.80 volume of titanium = (1.84 cm)(2.24 cm)(2.44 cm) = 10.1 cm3 density of titanium = 45.7 g/10.1 cm3 = 4.54 g/cm3 1.81 density = ỗ ổ 227,641 lb –1 ÷ = 0.591 lb gal è 385,265 gal ø ỉ 453.6 g ỉ 3785 mL–1 ỗ ữ = 0.0708 g mL ố lb ÷ø è gal–1 ø density = 0.591 lb gal1 ỗ ộ 0.3048 m ự ft 10.1 ft ´ 32.3 ft ´ 4.00 in ´ ´ê ú = 3.08 m 12 in ë ft û kg 1000 L 3.08 m3 ´ 0.686 ´ = 2112 kg L m3 1.82 1-11 Chapter Additional Exercises 1.83 1.299 1.84 28.5 CN$ US$ 3.785 L ´ ´ = 4.912 US$/gal L 1.001 CN$ gal km æ 0.6214 mi ổ 3.785 L ỗ ữỗ ữ = 67.0 mi gal–1 L è 1.00 km ø è 1.00 gal ø The first car has a mileage of 67.0 mi gal–1 and is more efficient than 31 mi gal–1 1.85 ỉ Mount Kenya Temperature 1.86 yd ÷ = 4760 yd è 0.9144 m ø æ yd ổ yd 4600 m ỗ 4700 m ç ÷ = 5000 yd ÷ = 5100 yd è 0.9144 m ø è 0.9144 m ø éæ °F ự ộổ F ự tF = ờỗ ữ tC + 32 Cỳ ờỗ ữ tC + 32 °Cú êëè °C ø úû êëè °C ø úû ỉ °F ỉ F =ỗ ữ tC ỗ ữ tC + 32 °C – 32 °C è °C ø ố C ứ ổ F =ỗ ÷ tC – tC è °C ø ổ F =ỗ ữ 4.0 C = 7.2 F ố C ứ Hausberg Tarn 4350 m ỗ If the density is in metric tons… æ 5.00 mL ö æ cm3 ö æ 1´108 tons ö æ 1000 kg ỉ 1´103 g 14 g = teaspoon ỗ ỗ ữỗ ữ ỗ ữ = 5.00 × 10 g è tsp ÷ø è mL ứ ố cm3 ứ ỗố ton ữứ ố kg ø If the density is in English tons… æ 5.00 mL ö æ cm3 ö æ 1´108 tons ỉ 2000 lbs ỉ 453.59 g = 4.54 ì 1014 g g = teaspoon ỗ ç ÷ç ÷ è tsp ÷ø è mL ứ ố cm3 ứ ỗố ton ữứ ỗố lb ÷ø ưỉ h ưỉ d ổ 1000 m ửổ 1s ữỗ ữỗ ữỗ ữ = 1.35 × 104 d è km øè 3.00 ´ 108 m øè 3600 s øè 24 h ø æ 3600 s ưỉ 24 h ưỉ 365 d light year = 3.00 ì 108 m/s ỗ ữỗ ữỗ ÷ = 9.46 × 1015 m/yr è h øè d ø è y ø æ 1000 m ưỉ light year light years = 3.50 × 1014 km ỗ ữ = 37.0 light years ữỗ ố km øè 9.46 ´ 1015 m ø 1.87 days = 3.50 ì 1014 km ỗ 1.88 (a) In order to determine the volume of the pycnometer, we need to determine the volume of the water that fills it We will this using the mass of the water and its density mass of water = mass of filled pycnometer – mass of empty pycnometer = 36.842 g – 27.314 g = 9.528 g ỉ mL ÷ = 9.556 mL è 0.99704 g ø volume = (9.528 g) ç 1-12 Chapter (b) We know the volume of chloroform from part (a) The mass of chloroform is determined in the same way that we determined the mass of water mass of chloroform = mass of filled pycnometer – mass of empty pycnometer = 41.428 g – 27.314 g = 14.114 g ỉ 14.114 g ÷ = 1.477 g/mL ố 9.556 mL ứ Density of chloroform = ỗ 1.89 For the message to get to Mars: ỉ 1.609 km ưỉ 1000 m ưỉ 1s ÷ = 1210 s ữỗ ữỗ ố mile ứố km ứố 3.00 ´ 108 m ø time = ( 225,000,000 miles) ç The reply would take the same amount of time, so the minimum time would be: 1210 s × = 2420 s 1.90 $7.35 $0.245 = 30 min ææ ö æ $0.245 ö 60 ö $ = ççç1 hr ´ ÷ + 45 ÷÷ç ÷ = $25.73 hr ø èè øè ø æ = $333.50 ỗ ữ = 1360 ố $0.245 ø $7.35 = 30 (a) (b) ( (c) 30 min = $7.35 $0.245 ) 1.91 æ 1.025 g ö æ lb ö æ 30.48 cm dsea water = ỗ = 64.0 lb ft ố cm3 ữứ ỗố 453.59 g ữứ ỗố ft ÷ø ỉ 2000 lbs ưỉ ft ÷ = 1.330 ´ 105 ft ft = 4255 tons ỗ ữỗỗ ố ton ứố 64.0 lb ÷ø ( ) 1.92 1.93 1.94 æ in ö æ 0.00011 lbs ö æ 453.6 g ö g = 2510 cm3 ỗ ữ = 7.6 g ữỗ ố 2.54 cm ữứ ỗố in3 ứ ố lb ø The experimental density most closely matches the known density of methanol (0.7914 g/mL) The density of ethanol is 0.7893 g/mL Melting point and boiling point could also distinguish these two alcohols, but not color ỉ 453.59 g ưỉ ft ử3 ổ cm3 ỗ ữ g/mL = 69.22 lb/ft3 ỗ lb ữỗ 30.48 cm ữ ỗ mL ÷ = 1.109 g/mL è øè ø è ø Since the density closely matches the known value, we conclude that this is an authentic sample of ethylene glycol 1.95 We solve by combining two equations: æ °F tF = ỗ (tC) + 32 F ố °C ÷ø tF = tC If tF = tC, we can use the same variable for both temperatures: æ F tC = ỗ (tC) + 32 F ố °C ÷ø 1-13 Chapter ỉ °F tc = ỗ (tC) + 32 F ố °C ÷ø -4 t = 32 c 5 tc = 32 = –40, therefore the answer is –40 °C 1.96 Both the Rankine and the Kelvin scales have the same temperature at absolute zero: R = K For converting from tF to TR: æ °C ÷ (tF – 32 °F) and è F ứ tC = ỗ therefore ổ C ữ ố1K ứ tC = (TK 273 K) ỗ ổ C ổ C ữ= ỗ ÷ (tF – 32 °F) è K ø è F ứ (TK 273 K) ỗ at TK = K = R ỉ °C ổ C ữ= ỗ ữ (tF 32 °F) è K ø è °F ø æ C 273 C = ỗ ữ (tF 32 °F) è °F ø (0 K – 273 K) ỗ 491 F = tF 32 F tF = –459 °F at absolute zero ỉ1R ÷ è F ứ TR = (tF + 459 F) ỗ Also, TR at absolute zero is R and So, the boiling point of water is 212 °F and in TR: ỉ1R ÷ = 671 R è °F ứ TR = (212 F + 459 F) ỗ 1.97 Sand Gold Mixture dsand = 2.84 g/mL dgold = 19.3 g/mL dmixture = 3.10 g/mL ỉ 1000 g ÷ = 1.00 × 103 g of mixture kg è ứ 1.00 kg mixture ỗ 1.00 ì 103 g of mixture = msand + mgold msand = (dsand)(Vsand) mgold = (dgold)(Vgold) 1.00 × 103 g of mixture = (dsand)(Vsand) + (dgold)(Vgold) 1.00 × 103 g of mixture = (2.84 g/mL)(Vsand) + (19.3 g/mL)(Vgold) Vmixture = Vsand + Vgold ỉmư d= ç ÷ èV ø ỉ ç 1.00 ´ 10 g ữ = 323 mL ỗ 3.10 g mL1 ÷ è ø Vsand + Vgold = 323 mL Vsand = 323 mL – Vgold 1-14 Chapter 1.00 × 103 g of mixture = (2.84 g/mL)(323 mL – Vgold) + (19.3 g/mL)(Vgold) 1.00 × 103 g of mixture = 917 g sand – (2.84 g/mL)(Vgold) + (19.3 g/mL)(Vgold) 1.00 × 103 g of mixture – 917 g sand = (16.5 g/mL)(Vgold) 5.0 mL = Vgold 1.00 × 103 g of mixture – 917 g sand = 83 g gold % mass of gold = 1.98 1.99 83 g gold ´100% =8.3% gold 1000 g total ỉ 30.48 cm ư2 Area of gold in cm = 14.6 ft ỗ ữ = 1.36 × 104 cm2 è ft ø ỉ cm ÷ = 3.39 cm3 Volume of gold in cm3 = 1.36 × 104 cm2 × 2.50 m ì ỗỗ ữ ố 110 mm ứ ổ mL ỉ 19.3 g ỉ troy ounce ö æ $1774.10 ö Cost of gold = 3.39 cm3 ì ỗ ữỗ ữỗ ữỗ ữ = $3732 ố cm3 ø è mL ø è 31.1035 g ø è troy ounce ø 2 ỉ 200 mg ổ g ổ cm3 ỗ ữ = 0.197 cm ố carat ữứ ỗố 1000 mg ÷ø è 3.51 g ø Volume of diamond = 3.45 carat ỗ V= pr 0.197 cm3 = pr r = 0.361 cm 2r = 0.722 cm 1-15 ... accuracy of a measured value is the closeness of that value to the true value of the quantity The precision of a number of repeated measurements of the same quantity is the closeness of the measurements... the volume of chloroform from part (a) The mass of chloroform is determined in the same way that we determined the mass of water mass of chloroform = mass of filled pycnometer – mass of empty pycnometer... ữ = 1.00 ì 103 g of mixture kg ố ứ 1.00 kg mixture ỗ 1.00 × 103 g of mixture = msand + mgold msand = (dsand)(Vsand) mgold = (dgold)(Vgold) 1.00 × 103 g of mixture = (dsand)(Vsand) + (dgold)(Vgold)
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