Chemistry

Chapter 3

1. Explore some aspects of measurements and how you report them. Describe an example that would correspond to an everyday example of reporting a measurement (e.g., what time you will meet someone, how many people attended an event) and describe the way a scientist would report this value, including a description of the precision, accuracy, and use of significant figures.

45. Write the chemical formula for each of the following compounds. List the

symbols for the elements in the order that the elements are mentioned in the

description.

a. a compound with molecules that consist of two phosphorus atoms and five

oxygen atoms.

b. a compound with molecules that consist of two hydrogen atoms and one

sulfur atom.

c. a compound that contains three calcium atoms for every two nitrogen

atoms.

d. a compound with molecules that consist of 12 carbon atoms, 22 hydrogen

atoms, and 11 oxygen atoms.

55. Classify each of the following as either a molecular compound or an ionic

compound.

a. cadmium fluoride, (a starting material for lasers)

b. sulfur dioxide, (a food additive that inhibits browning and bacterial

growth)

71. Compare and contrast the information given in the Lewis structure, the

space‑filling model, the ball‑and‑stick model, and the geometric sketch of an

ammonia molecule, .

73. What are the particles that form the basic structure of water? Describe the

attraction that holds these particles together. Draw a rough sketch that shows the

attraction between two water molecules

81. Write the name for each of the following chemical formulas.

a. (a commercial bleaching agent)

b. (in natural gas)

c. HI (when dissolved in water, used to make pharmaceuticals)

d. (for doping semiconductors)

e. BrCl (an industrial disinfectant)

83. Write the chemical formula for each of the following names.

a. ammonia (a household cleaner when dissolved in water)

b. tetraphosphorus hexasulfide (used in organic chemical reactions)

c. iodine monochloride (used for organic synthesis)

d. hydrogen chloride (used to make hydrochloric acid)

97. Write the name for each of these chemical formulas.

a. (a nematocide—that is, it kills certain parasitic worms.)

b. (in signal flares)

c. (used in gold plating)

d. (in pharmaceutical preparations)

e. (in hair wave formulations)

99. Write chemical formulas for each of the following names.

a. barium chloride (used in manufacture of white leather)

b. cobalt(III) oxide (used in coloring enamels)

c. manganese(II) chloride (used in pharmaceutical preparations)

d. iron(III) acetate (a medicine)

e. chromium(III) phosphate (in paint pigments)

f. magnesium hydrogen phosphate (a laxative)

Chapter 8

59. Complete the following calculations and report your answers with the correct

number of significant figures. The exponential factors, such as , are exact, and

the 5280 in part (c) is exact. All the other numbers are not exact.

a. =

b.

c.

67. The density of whole blood is 1.05 g/mL. A typical adult has about 5.5 L of

whole blood. What is the mass in pounds of this amount of whole blood?

108. Absolute zero, the lowest possible temperature, is exactly 0 K. What is this

temperature in °C?…in °F?

Chapter 9

30. A multivitamin tablet contains 40 milligrams of potassium. How many moles of

potassium does each tablet contain?

32. A multivitamin tablet contains 1.93 × mole of chromium. How many micrograms of chromium does each tablet contain?

45. Many famous “rubies” are in fact spinels, which look like rubies but are far less valuable. Spinels consist primarily of , whereas rubies are primarily . If the Timur Ruby, a 361-carat spinel, were pure , how many moles of would it contain? (There are exactly 5 carats per gram.)

49. Calcium phosphide is used to make fireworks. Write a conversion factor that converts between moles of calcium ions in calcium phosphide, , and moles of .

57. Manganese metal is produced from the manganese(III) oxide, ,which is found in manganite, a manganese ore. The manganese is reduced from its +3 oxidation state in to the zero oxidation state of the uncharged metal by reacting the with a reducing agent such as aluminum or carbon. How many pounds of manganese are in 1.261 tons of ? (1 ton = 2000 pounds)

72. About 40 different substances called organophosphorus compounds are registered in the United States as insecticides. They are considered less damaging to the environment than some other insecticides because they breakdown relatively rapidly in the environment. The first of these organophosphorus insecticides to be produced was tetraethyl pyrophosphate, TEPP, which is 33.11% carbon, 6.95% hydrogen, 38.59% oxygen, and 21.35% phosphorus. It has a molecular mass of 290.190. What is the molecular formula for TEPP?

Chapter 10

42. Aniline, , which is used to make antioxidants, can be formed from

nitrobenzene, , in the following reaction.

4+ 9Fe + 4 4 + 3

FeCl2

a. What is the maximum mass of aniline, , formed in the reaction

of 810.5 g of nitrobenzene, , with 985.0 g of Fe and 250 g of

?

b. Explain why two of these substances are in excess and one is limiting

61. Consider the neutralization reaction that takes place when hydrochloric acid

reacts with solid nickel(II) carbonate.

a. Write a conversion factor that relates moles of HCl to moles of for

this reaction.

b. What is the minimum volume of 6.0 M HCl necessary to react completely

with 14.266 g of solid nickel(II) carbonate, ?