Classify each of the following statements as a hypothesis,

The composition of pennies has changed over the years, depending on a number of factors, including the availability of various metals. A penny minted in 1825 was pure copper; a penny minted in 1860 was 88 percent copper and 12 percent nickel; a penny minted in 1965 was 95 percent copper and 5 percent zinc; and a penny minted today is 97.5 percent zinc and 2.5 percent copper. Given that the densities of copper, nickel, and zinc are \(8.92 \mathrm{~g} / \mathrm{cm}^{3}, 8.91 \mathrm{~g} / \mathrm{cm}^{3}\) and \(7.14 \mathrm{~g} / \mathrm{cm}^{3}\), respectively, determine the density of each penny.

Give an example for each of the following terms: (a) matter, (b) substance, (c) mixture.

Problem 7QP Give an example of a homogeneous mixture and an example of a heterogeneous mixture.

Problem 12QP How does an intensive property differ from an extensive property?

Determine whether each of the following describes a physical change or a chemical change: (a) The helium gas inside a balloon tends to leak out after a few hours. (b) A flashlight beam slowly gets dimmer and finally goes out. (c) Frozen orange juice is reconstituted by adding water to it. (d) The growth of plants depends on the sun’s energy in a process called photosynthesis. (e) A spoonful of sugar dissolves in a cup of coffee.

Describe the three temperature scales used in everyday life and in the laboratory: the Fahrenheit, Celsius, and Kelvin scales.

Problem 27QP The density of water at 40°C is 0.992 g/mL. What is the volume of 2.50 g of water at this temperature?

Problem 33QP Indicate which of the following numbers is an exact number: (a) 50,247 tickets were sold at a sporting event; (b) 750 mL of water was used to make a birthday cake; (c) 10 eggs were used to make a breakfast; (d) 0.41 g of oxygen was inhaled in each breath; (e) Earth orbits the sun every 365.24 days.

Problem 39QP Express the answers to the following calculations in scientific notation: (a) 0.0095 + (8.5 × 10?3) (b) 653 ÷ (5.75 × 10?8) (c) 850,000 ? (9.0 × 105) (d) (3.6 × 10?4) × (3.6 × 106)

Problem 40QP Report the quantity being measured to the appropriate number of significant figures.

Problem 45QP Carry out the following operations as if they were calculations of experimental results, and express each answer in the correct units with the correct number of significant figures: (a) 7.310 km ÷ 5.70 km (b) (3.26 × 10?3mg) ? (7.88 × 10?5 mg) (c) (4.02 × 106 dm) + (7.74 × 107 dm)

Problem 51QP Carry out the following conversions: (a) 242 lb to milligrams. (b) 68.3 cm3 to cubic meters, (c) 7.2 m3 to liters, (d) 28.3 µg to pounds.

A slow jogger runs a mile in 13 min. Calculate the speed in (a) in/s, (b) m/min, (c) km/h (1 mi = 1609 m; 1 in = 2.54 cm).

Problem 59QP The current speed limit on some highways in the United States is 65 mph. What is the speed limit in kilometers per hour (1 mi = 1609 m)?

Problem 64QP Aluminum is a lightweight metal (density = 2.70 g/cm3) used in aircraft construction, high-voltage transmission lines, beverage cans, and foils. What is its density in kg/m3?

Problem 75AP The following procedure was used to determine the volume of a flask. The flask was weighed dry and then filled with water. If the masses of the empty flask and filled flask were 56.12 g and 87.39 g. respectively, and the density of water is 0.9976 g/cm3. calculate the volume of the flask in cubic centimeters.

Problem 70AP Give one qualitative and one quantitative statement about each of the following: (a) water, (b) carbon, (c) iron, (d) hydrogen gas, (e) sucrose (cane sugar), (f) table salt, (g) mercury, (h) gold, (i) air.

Problem 76AP The speed of sound in air at room temperature is about 343 m/s. Calculate this speed in miles per hour (1 mi = 1609 m).

Problem 81AP The medicinal thermometer commonly used in homes can be read to ±0.1 °F, whereas those in the doctor’s office may be accurate to ±0.1 °C. Percent error is often expressed as the absolute value of the difference between the true value and the experimental value, divided by the true value: The vertical lines indicate absolute value. In degrees Celsius, express the percent error expected from each of these thermometers in measuring a person’s body temperature of 38.9°C.

Problem 87AP The total volume of seawater is 1.5 × 1021 L. Assume that seawater contains 3.1 percent sodium chloride by mass and that its density is 1.03 g/mL. Calculate the total mass of sodium chloride in kilograms and in tons (1 ton = 2000 lb: 1 lb = 453.6 g).

Problem 92AP Venus, the second closest planet to the sun, has a surface temperature of 7.3 × 102 K. Convert this temperature to degrees Celsius and degrees Fahrenheit.

Problem 93AP Chalcopyrite, the principal ore of copper (Cu), contains 34.63 percent Cu by mass. How many grams of Cu can be obtained from 5.11 × 103 kg of the ore?

Problem 98AP A sample of DNA, the genetic material of life, was estimated to have a mass of 308,859 amu. What is this mass in grams? The average width of a DNA double strand is approximately 22 Å to 26 Å. Express this range of widths in meters.

A gas company in Massachusetts charges $1.30 for \(15.0 \mathrm{ft}^3\) of natural gas. (a) Convert this rate to dollars per liter of gas. (b) If it takes \(0.304 \mathrm{ft}^3\) of gas to boil a liter of water, starting at room temperature \(\left(25^{\circ} \mathrm{C}\right)\), how much would it cost to boil a 2.1-L kettle of water?

Problem 110AP A chemist mixes two liquids A and B to form a homogeneous mixture. The densities of the liquids are 2.0514 g/mL for A and 2.6678 g/mL for B. When she drops a small object into the mixture, she finds that the object becomes suspended in the liquid; that is, it neither sinks nor floats. If the mixture is made of 41.37 percent A and 58.63 percent B by volume, what is the density of the object? Can this procedure be used in general to determine the densities of solids? What assumptions must be made in applying this method?

Problem 112AP TUMS is a popular remedy for acid indigestion. A typical TUMS tablet contains calcium carbonate plus some inert substances. When ingested, it reacts with the gastric juice (hydrochloric acid) in the stomach to give off carbon dioxide gas. When a l.328-g tablet reacted with 40.00 ml. of hydrochloric acid (density = 1. 140 g/mL), carbon dioxide gas was given off and the resulting solution weighed 46.699 g. Calculate the number of liters of carbon dioxide gas released if its density is l.8l g/L.

Problem 2QP Explain what is meant by the scientific method.

Using examples, explain the difference between a physical property and a chemical property.

Problem 16QP Determine whether each of the following describes a physical change or a chemical change: (a) A soda loses its fizz and goes flat, (b) A bruise develops on a football player’s arm and gradually changes color. (c) A pile of leaves is burned, (d) Frost forms on a windshield after a cold night, (e) Wet clothes are hung out to dry in the sun.

Problem 24QP The density of ethanol, a colorless liquid that is commonly known as grain alcohol, is 0.798 g/mL. Calculate the mass of 17.4 mL of the liquid.

Convert the following temperatures to kelvins: (a) \(113^\circ \mathrm C\), the melting point of sulfur; (b) \(37^\circ \mathrm C\), the normal body temperature; (c) \(357^\circ \mathrm C\), the boiling point of mercury.

Problem 36QP Express the following numbers in scientific notation: (a) 0.000000027, (b) 356, (c) 47,764, (d) 0.096.

Problem 41QP Report each temperature to the appropriate number of significant figures.

Problem 42QP Determine the number of significant figures in each of the following measurements: (a) 4867 mi, (b) 56 mL, (c) 60,104 tons, (d) 2900 g, (e) 40.2 g/cm3, (f) 0.0000003 cm, (g) 0.7 min, (h) 46 amu.

Problem 46QP Three students (A, B, and C) are asked to determine the volume of a sample of ethanol. Each student measures the volume three times with a graduated cylinder. The results in milliliters are: A (87.1, 88.2, 87.6); B (86.9, 87.1, 87.2); C (87.6, 87.8, 87.9). The true volume is 87.0 mL. Comment on the precision and the accuracy of each student’s results.

Problem 68AP A piece of metal with a mass of 13.2 g was dropped into a graduated cylinder containing 17.00 mL of water. The graduated cylinder after the addition of the metal is shown. Determine the density of the metal to the appropriate number of significant figures.

Carry out the following conversions: (a) 185 nm to meters, (b) 4.5 billion years (roughly the age of Earth) to seconds (assume exactly 365 days in a year), (c) 71.2 \(\mathrm{cm}^{3}\) to cubic meters, (d) 88.6 \(\mathrm{m}^{3}\) to liters.

Problem 71AP In 2004, about 95.0 billion lb of sulfuric acid were produced in the United States. Convert this quantity to tons.

Problem 82AP Vanillin (used to flavor vanilla ice cream and other foods) is the substance whose aroma the human nose detects in the smallest amount. The threshold limit is 2.0 × 10?11 g per liter of air. If the current price of 50 g of vanillin is $112, determine the cost to supply enough vanillin so that the aroma could be detected in a large aircraft hangar with a volume of 5.0 × 107 ft3.

Problem 88AP Magnesium (Mg) is a valuable metal used in alloys, in batteries, and in the manufacture of chemicals. It is obtained mostly from seawater. which contains about 1.3 g of Mg for every kilogram of seawater. Referring to Problem 1.89. calculate the volume of seawater (in liters) needed to extract 8.0 × 104 tons of Mg, which is roughly the annual production in the United States.

Problem 99AP Pheromones are compounds secreted by females of many insect species to attract mates. Typically. 1.0 × 10?8 g of a pheromone is sufficient to reach all targeted males within a radius of 0.50 mi. Calculate the density of the pheromone (in grams per liter) in a cylindrical air space having a radius of 0.50 mi and a height of 40 ft (volume of a cylinder of radius r and height h is ?r2h).

Problem 107AP A 250-mL glass bottle was filled with 242 mL of water at 20°C and tightly capped. It was then left outdoors overnight, where the average temperature was ?5°C. Predict what would happen. The density of water at 20°C is 0.998 g/cm3 and that of ice at ?5°C is 0.916g/cm3.

Problem 1QP Define the terms chemistry and matter.

Problem 5QP Classify each of the following statements as a hypothesis, law, or theory. (a) The force acting on an object is equal to its mass times its acceleration. (b) The universe as we know it started with a big bang. (c) There are many civilizations more advanced than ours on other planets.

Problem 3QP What is the difference between a hypothesis and a theory?

Classify each of the following statements as a hypothesis, law, or theory. (a) Beethoven’s contribution to music would have been much greater if he had married. (b) An autumn leaf gravitates toward the ground because there is an attractive force between the leaf and Earth. (c) All matter is composed of very small particles.

What is the difference between a qualitative property and a quantitative property?

Classify each of the following as a pure substance, a homogeneous mixture, or a heterogeneous mixture: (a) seawater, (b) helium gas, (c) salt, (d) diet cola, (e) a milkshake, (f) bottled water, (g) concrete, (h) 24K gold, (i) liquid nitrogen.

Problem 8QP Identify each of the diagrams shown here as a solid, liquid, gas, or mixture of two substances.

Determine which of the following properties are intensive and which are extensive: (a) length, (b) volume, (c) temperature, (d) mass.

Problem 18QP Name the SI base units that are important in chemistry, and give the SI units for expressing the following: (a) length, (b) volume, mass, (d) time, (e) temperature.

Problem 23QP Bromine is a reddish brown liquid. Calculate its density (in g/mL) if 586 g of the substance occupies 188 mL.

Problem 34QP Define significant figure. Discuss the importance of using the proper number of significant figures in measurements and calculations.

Problem 30QP Convert the following temperatures to degrees Celsius: (a) 77 K, the boiling point of liquid nitrogen; (b) 4.2 K, the boiling point of liquid helium; (c) 601 K, the melting point of lead.

Express the answers to the following calculations in scientific notation: (a) \(145.75+\left(2.3 \times 10^{-1}\right)\) (b) \(79,500 \div\left(2.5 \times 10^{2}\right)\) (c) \(\left(7.0 \times 10^{-3}\right)-\left(8.0 \times 10^{-4}\right)\) (d) \(\left(1.0 \times 10^{4}\right) \times\left(9.9 \times 10^{6}\right)\)

Carry out the following operations as if they were calculations of experimental results, and express each answer in the correct units with the correct number of significant figures: (a) 5.6792 m + 0.6 m + 4.33 m (b) 3.70 g – 2.9133 g (c) 4.51 cm × 3.6666 cm

Determine the number of significant figures in each of the following measurements: (a) 0.006 L, (b) 0.0605 dm, \(\text { (c) } 60.5 \mathrm{mg} \text {, (d) } 605.5 \mathrm{~cm}^{2} \text {, (e) } 9.60 \times 10^{3} \mathrm{~g} \text {, (f) } 6 \mathrm{~kg} \text {, }\), \(\text { (g) } 60 \mathrm{~m} \text {, (h) } 1.42 \text { A }\).

Problem 50QP Carry out the following conversions: (a) 22.6 m to decimeters, (b) 25.4 mg to kilograms, (c) 556 mL to liters, (d) 10.6 kg/m3 to g/cm3.

Carry out the following conversions: (a) 242 amu to grams, (b) 87 amu to kilograms, (c) 2.21 Å to meters, (d) 1.73 Å to nanometers. [See page 10 for conversion factors for atomic mass units (amu) and angstroms (Å).]

A 6.0-ft person weighs 168 lb. Express this person’s height in meters and weight in kilograms (1 lb = 453.6 g; 1 m = 3.28 ft).

Problem 69AP Which of the following statements describe physical properties and which describe chemical properties? (a) Iron has a tendency to rust. (b) Rainwater in industrialized regions tends to be acidic, (c) Hemoglobin molecules have a red color, (d) When a glass of water is left out in the sun, the water gradually disappears, (e) Carbon dioxide in air is converted to more complex molecules by plants during photosynthesis. •

Problem 77AP A piece of silver (Ag) metal weighing 194.3 g is placed in a graduated cylinder containing 242.0 mL of water. The volume of water now reads 260.5 mL. From these data calculate the density of silver.

Problem 83AP Suppose that a new temperature scale has been devised on which the melting point of ethanol (?117.3°C) and the boiling point of ethanol (78.3°C) are taken as 0°S and 100°S, respectively, where S is the symbol for the new temperature scale. Derive an equation relating a reading on this scale to a reading on the Celsius scale. What would this thermometer read at 25°C?

Problem 94AP It has been estimated that 8.0 × 104 tons of gold have been mined. Assume gold costs $1100 per ounce. What is the total value of this quantity of gold?

Chlorine is used to disinfect swimming pools. The recommended concentration for this purpose is 1 ppm chlorine, or 1 g of chlorine per million grams of water. Calculate the volume of a chlorine solution (in milliliters) a homeowner should add to her swimming pool if the solution contains 6.0 percent chlorine by mass and there are \(2.0 \times 10^{4}\) gallons (gal) of water in the pool (1 gal = 3.79 L; assume the density of both the water and the chlorine solution to be = 1.0 g/mL).

Problem 106AP A bank teller is asked to assemble $1 sets of coins for his clients. Each set is made up of three quarters, one nickel, and two dimes. The masses of the coins are quarter, 5.645 g: nickel, 4.967 g; and dime, 2.316 g. What is the maximum number of sets that can be assembled from 33.871 kg of quarters, 10.432 kg of nickels, and 7.990 kg of dimes? What is the total mass (in grams) of the assembled sets of coins?

Problem 108AP Bronze is an alloy made of copper (Cu) and tin (Sn). Calculate the mass of a bronze cylinder of radius 6.44 cm and length 44.37 cm. The composition of the bronze is 79.42 percent Cu and 20.58 percent Sn and the densities of Cu and Sn are 8.94 g/cm3 and 7.31 g/cm3, respectively. What assumption should you make in this calculation?

Problem 113AP Determine (a) the temperature at which the Celsius and Fahrenheit values are numerically equal, and (b) the temperature at which the Kelvin and Fahrenheit values are numerically equal, (c) Is there a temperature at which the Celsius and Kelvin values are numerically equal? Explain.

The hottest temperature ever recorded on Earth was \(136^{\circ} \mathrm{F}\) (recorded at Al ’Aziziyah, Libya on September 13, 1922). Express this temperature in degrees Celsius and in kelvins.

Problem 14QP Determine whether the following statements describe chemical or physical properties: (a) Oxygen gas supports combustion, (b) Ingredients in antacids reduce acid reflux, (c) Water boils above 100°C in a pressure cooker, (d) Carbon dioxide is denser than air. (e) Uranium combines with fluorine to form a gas.

Problem 15QP Classify the following as qualitative or quantitative statements, giving your reasons, (a) The sun is approximately 93 million mi from Earth, (b) Leonardo da Vinci was a better painter than Michelangelo, (c) Ice is less dense than water, (d) Butter tastes better than margarine, (e) A stitch in time saves nine.

Problem 19QP Write the numbers represented by the following prefixes: (a) mega-, (b) kilo-, (c) deci-, (d) centi-, (e) milli-, (f) micro-, (g) nano-, (h) pico-.

Problem 20QP What units do chemists normally use for the density of liquids and solids? For the density of gas? Explain the differences.

Problem 21QP What is the difference between mass and weight? If a person weighs 168 lb on Earth, about how much would the person weigh on the moon?

Problem 25QP Convert the following temperatures to degrees Celsius or Fahrenheit: (a) 95°F, the temperature on a hot summer day; (b) 12°F, the temperature on a cold winter day; (c) a 103°F fever: (d) a furnace operating at 1852°F: (e) -273.15°C (theoretically the lowest attainable temperature).

Problem 26QP (a) Normally the human body can endure a temperature of 105°F for only short periods of time without permanent damage to the brain and other vital organs. What is this temperature in degrees Celsius? (b) Ethylene glycol is a liquid organic compound that is used as an antifreeze in car radiators. It freezes at ?11,5°C. Calculate its freezing temperature in degrees Fahrenheit, (c) The temperature on the surface of the sun is about 6300°C. What is this temperature in degrees Fahrenheit?

The density of platinum is \(21.5 \mathrm{g} / \mathrm{cm}^{3}\) at 25°C. What is the volume of 87.6 g of Pt at this temperature?

Problem 31QP A 37.2-g sample of lead (Pb) pellets at 20°C is mixed with a 62.7-g sample of lead pellets at the same temperature. What are the final mass, temperature, and density of the combined sample? The density of Pb at 20°C is 11.35 g/cm3.

Problem 32QP A student pours 44.3 g of water at 10°C into a beaker containing 115.2 g of water at I0°C. What are the final mass, temperature, and density of the combined water? (The density of water at 10°C is 1.00 g/mL.)

Problem 35QP Distinguish between the terms accuracy and precision. In general, explain why a precise measurement does not always guarantee an accurate result.

Express the following numbers as decimals: (a) \(1.52 \times 10^{-2}\), (b) \(7.78 \times 10^{-8}\), (c) \(3.29 \times 10^{-6}\), (d) \(8.41 \times 10^{-1}\).

Problem 47QP Three apprentice carpenters (X, Y, and Z) are assigned the task of measuring the width of a doorway. Each one makes three measurements. The results in inches are X (31.5, 31.6, 31.4); Y (32.8, 32.3, 32.7); Z (31.9, 32.2, 32.1). The true width is 32.0 in. Comment on the precision and the accuracy of each carpenter’s measurements.

Problem 48QP The density of the metal bar shown is 7.89 g/cm3. Determine its mass to the appropriate number of significant figures.

Problem 49QP The following shows an experiment used to determine the density of a gas. The evacuated bulb has a volume of 111.5 mL. It was weighed, filled with the gas, and weighed again. Determine the density of the gas to the appropriate number of significant figures.

Problem 53QP Carry out the following conversions: (a) 1.1 × 10-22 g to atomic mass units, (b) 1.08 × 10-29 kg to atomic mass units, (c) 8.3 × 10-9 in to angstroms, (d) 132 pm to angstroms. [See page 10 for conversion factors for atomic mass units (amu) and angstroms (Å).]

Problem 54QP The average speed of helium at 25°C is 1255 m/s. Convert this speed to miles per hour (mph).

Problem 55QP How many seconds are there in a solar year (365.24 days)?

Problem 56QP How many minutes does it take light from the sun to reach Earth? (The distance from the sun to Earth is 93 million mi; the speed of light is 3.00 × 108 m/s.)

Problem 60QP For a fighter jet to take off from the deck of an aircraft carrier, it must reach a speed of 62 m/s. Calculate the speed in miles per hour.

Problem 61QP The “normal” lead content in human blood is about 0.40 part per million (that is, 0.40 g of lead per million grams of blood). A value of 0.80 part per million (ppm) is considered to be dangerous. How many grams of lead are contained in 6.0 × 103 g of blood (the amount in an average adult) if the lead content is 0.62 ppm?

Problem 62QP Carry out the following conversions: (a) 1.42 light-years to miles (a light-year is an astronomical measure of distance—the distance traveled by light in a year, or 365 days; the speed of light is 3.00 × 10s m/s), (b) 32.4 yd to centimeters, (c) 3.0 × 1010 cm/s to ft/s.

Problem 65QP The density of ammonia gas under certain conditions is 0.625 g/L. Calculate its density in g/cm3.

Problem 66QP A human brain weighs about 1 kg and contains about 1011 cells. Assuming that each cell is completely filled with water (density = 1 g/mL). calculate the length of one side of such a cell if it were a cube. If the cells are spread out into a thin layer that is a single cell thick, what is the surface area in square meters?

Using the appropriate number of significant figures, report the length of the blue rectangle (a) using the ruler shown above the rectangle and (b) using the ruler shown below the rectangle.

In determining the density of a rectangular metal bar, a student made the following measurements: length, 8.53 cm; width, 2.4 cm; height, 1.0 cm; mass, 52.7064 g. Calculate the density of the metal to the correct number of significant figures.

Calculate the mass of each of the following: (a) a sphere of gold with a radius of 10.0 cm (volume of a sphere with a radius r is V = \(\frac{4}{3} \pi r^{3}\); density of gold = \(19.3 \mathrm{~g} / \mathrm{cm}^{3}\)); (b) a cube of platinum of edge length 0.040 mm (density = \(21.4 \mathrm{~g} / \mathrm{cm}^{3}\)); (c) 50.0 mL of ethanol (density = 0.798 g/mL).

Problem 74AP A cylindrical glass tube 12.7 cm in length is filled with mercury (density = 13.6 g/mL). The mass of mercury needed to fill the tube is 105.5 g. Calculate the inner diameter of the tube (volume of a cylinder of radius r and length h is

Problem 78AP The experiment described in Problem 1.79 is a crude but convenient way to determine the density of some solids. Describe a similar experiment that would enable you to measure the density of ice. Specifically, what would be the requirements for the liquid used in your experiment?

Problem 79AP A lead sphere has a mass of 1.20 × 104 g, and its volume is 1.05 × 103 cm3. Calculate the density of lead.

Problem 80AP Lithium is the least dense metal known (density = 0.53 g/cm3). What is the volume occupied by 1.20 × 103 g of lithium?

At what temperature does the numerical value on the Celsius scale equal that on the temperature scale described in Problem 1.83?

Problem 85AP A resting adult requires about 240 mL of pure oxygen per minute and breathes about 12 times every minute. If inhaled air contains 20 percent oxygen by volume and exhaled air 16 percent, what is the volume of air per breath? (Assume that the volume of inhaled air is equal to that of exhaled air.)

(a) Referring to Problem 1.85, calculate the total volume (in liters) of air an adult breathes in a day. (b) In a city with heavy traffic, the air contains \(2.1 \times 10^{-6} \mathrm{~L}\) of carbon monoxide (a poisonous gas) per liter. Calculate the average daily intake of carbon monoxide in liters by a person.

The unit “troy ounce” is often used for precious metals such as gold and platinum (1 troy ounce = 31.103 g). (a) A gold coin weighs 2.41 troy ounces. Calculate its mass in grams. (b) Is a troy ounce heavier or lighter than an ounce (1 lb = 16 oz; 1 lb = 453.6 g)?

Problem 90AP The surface area and average depth of the Pacific Ocean are 1.8 × 10s km2 and 3.9 × 103m, respectively. Calculate the volume of water in the ocean in liters.

Problem 91AP Calculate the percent error for the following measurements: (a) The density of alcohol (ethanol) is found to be 0.802 g/mL (true value = 0.798 g/mL). (b) The mass of gold in an earring is analyzed to be 0.837 g (true value = 0.864 g).

One gallon of gasoline in an automobile’s engine produces on the average 9.5 kg of carbon dioxide, which is a greenhouse gas; that is, it promotes the warming of Earth’s atmosphere. Calculate the annual production of carbon dioxide in kilograms if there are 40 million cars in the United States and each car covers a distance of 5000 mi at an average consumption rate of 20 miles per gallon.

A sheet of aluminum foil has a total area of \(1.000 \mathrm{ft}^2\) and a mass of \(3.636 \mathrm{~g}\). What is the thickness of the foil in millimeters (density of aluminum \(=2.699 \mathrm{~g} / \mathrm{cm}^3\))?

Problem 97AP The world’s total petroleum reserve is estimated at 2.0 × 1022 joules [a joule (J) is the unit of energy where 1 J = 1 kg • m2/s2]. At the present rate of consumption, 1.8 × 1020 joules per year (J/yr), how long would it take to exhaust the supply?

Problem 101AP A graduated cylinder is filled to the 40.00-mL mark with a mineral oil. The masses of the cylinder before and after the addition of the mineral oil are 124.966 g and 159.446 g, respectively. In a separate experiment, a metal ball bearing of mass 18.713 g is placed in the cylinder and the cylinder is again filled to the 40.00-mL mark with the mineral oil. The combined mass of the ball bearing and mineral oil is 50.952 g. Calculate the density and radius of the ball bearing (volume of a sphere of radius r is ).

In water conservation, chemists spread a thin film of a certain inert material over the surface of water to cut down on the rate of evaporation of water in reservoirs. This technique was pioneered by Benjamin Franklin three centuries ago. Franklin found that 0.10 mL of oil could spread over the surface of water about 40 \(m^{2}\) in an area. Assuming that the oil forms a monolayer, that is, a layer that is only one molecule thick, estimate the length of each oil molecule in nanometers \(\left(1 \mathrm{~nm}=1 \times 10^{-9} \mathrm{~m}\right)\).

A chemist in the nineteenth century collected a sample of unknown matter. In general, do you think it would be more difficult to prove that it is a pure substance or a mixture? Explain

Problem 105AP You are given a liquid. Briefly describe the steps you would take to show whether it is a pure substance or a homogeneous mixture.

Problem 109AP Lead poisoning affects nearly every system in the body and can occur with no symptoms, potentially causing it to go undiagnosed. The primary source of lead exposure is the deteriorating lead-based paint in older homes, where young children are particularly vulnerable to exposure because of their tendency to put things in their mouths. In addition to the prevention of exposure, the Centers for Disease Control (CDC) guidelines recommend that public health actions be initiated when lead levels exceed 10 micrograms of lead per deciliter of blood. Determine whether or not the following lead levels would exceed the CDC’s threshold level: (a) 3.0 × 10-4 grams per liter of blood, (b) 2.0 × 10-5 milligrams per milliliter of blood, (c) 6.5 × 10-8 grams per cubic centimeter.

Problem 111AP In January of 2009, the National Aeronautics and Space Administration (NASA) reported that a planet in our galaxy, known as HD 80606b, underwent a temperature change from 980°F to 2240°F over the course of six hours, (a) Convert these temperatures and the range they span to degrees Celsius, and to kelvins. (b) Determine the rate of temperature change per second in degrees Fahrenheit, degrees Celsius, and kelvins.

Problem 115AP The drug cidofovir is approved by the Federal Drug Administration (FDA) for the treatment of certain viral infections of the eye in patients with compromised immune systems. It is distributed in vials containing 375 mg of the drug dissolved in 5 mL of water. The manufacturer specifies that the drug should be kept at room temperature (68°F?77°F). The vial contents are first diluted with saline and then administered intravenously with a recommended dosage of 5 mg cidofovir per kilogram of body weight, (a) Convert cidofovir’s recommended storage-temperature range to the Celsius scale, (b) If the fluid in a single vial of cidofovir has a volume of 5.00 mL and a mass of 5.89 g, what is the density of the fluid, in g/mL. to the appropriate number of significant figures? (c) Convert the density in part (b) to g/L and to kg/m3, (d) What mass of cidofovir should be administered to a 185-lb man?