AP Chemistry Review Assignment
Brown and LeMay: Chemistry the Central Science, 11th edition
Chapter 1 “Introduction: Matter and Measurement” Assignments
Classification and Properties of Matter
13. Classify each of the following as a pure substance or a mixture; if a mixture, indicate whether it is homogeneous
or heterogeneous:
a) rice pudding Heterogeneous mixture
b) seawater Homogeneous mixture unless there are undissolved particles such as sand, then heterogeneous
c) magnesium Element
d) gasoline Homogeneous mixture
17. A solid white substance A is heated strongly in the absence of air. It decomposes to form a new white substance B and a gas C. The gas has exactly the same properties as the product obtained when carbon is burned in an excess of oxygen. Based on these observations, can we determine whether solids A and B and the gas C are elements or compounds?
.A – compound B – cannot be determined, C - compound
19. In the process of attempting to characterize a substance, a chemist makes the following observations: The substance is a silvery white, lustrous metal. It melts at 649oC and boils at 1105oC. Its density at 20oC is 1.738 g/cm3. The substance burns in air, producing an intense white light. It reacts with chlorine to give a brittle white solid. The substance be pounded into thin sheets or drawn into wires. It is a good conductor of electricity. Red – Physical, Green - Chemical
Units of Measurement
26. Use the appropriate metric prefixes to write the following measurements without use of exponents:
a) 2.3 x 10-2 L 23 mL
b) 4.7 x 10-4 g .47 mg
c) 1.85 x 10-12 m 1.85 pm
27. a) A sample of carbon tetrachloroethylen, a liquid once used in dry cleaning that is being phased out because of its potential to cause cancer, has a mass of 40.55 g and a volume of 25.0 mL at 25oC. What is its density at this temperature? Will carbon tetrachloroethylene float on water? 1.62 g/mL, it will sink in water
b) Carbon dioxide is a gas at room temperature and pressure. However, carbon dioxide can be put under pressure to become a “supercritical fluid” that is a much safer dry-cleaning agent than tetrachloroethylene. At a certain pressure, the density of supercritical carbon dioxide is 0.469 g/cm3. What is the mass of a 25.0 mL sample of supercritical CO2 at this pressure? 11.7 grams
Uncertainty in Measurement
35. Indicate which of the following are exact numbers: b, d, and e
a) the mass of a 3 x 5 index card
b) the number of ounces in a pound
c) the volume of a cup of coffee
d) the number of inches in a mile
e) the number of microseconds in a week
37. What is the number of significant figures in each of the following measured quantities:
a) 601 kg 3
b) 0.054 s 2
c) 6.3050 cm 5
d) 0.0105 L 3
e) 7.0500 x 10-3 m3 5
41. Carry out the following operations, and express the answers with the appropriate numbers of significant figures:
a) 14.3505 + 2.65 = 16.97
b) 952.7 - 140.7389 = 812.0
c) (3.29 x 104)(0.2501) = 8230
d) 0.0588/0.677 = 0.869
Dimensional Analysis
50. Perform the following conversions:
a) 5.00 days to s 216,000 s
b) 0.0550 mi to m 88.5 m
c) $1.89/gal to dollars per liter $0.499
54. a) If an electric car is capable of going 225 km on a single charge, how many charges will it need to travel from Seattle, Washington to San Diego, California, a distance of 1257mi, assuming that the trip begins with a full charge? 3.47 charges
b) If a migrating loon flies at an average speed of 14 m/s, what is its average speed in mi/hr? 31 mi/hr
Chapter 2 “Atoms, Molecules and Ions” Assignments
The Atomic Theory and The Discovery of Atomic Structure
1. A negatively charged particle is caused to move between two electrically charged plates, as illustrated below
a) Why does the path of the charged particle bend? The path of the charged particle bends because it is repelled by the negatively charged plate and attracted to the positively charged plate.
b) What is the sign of the electrical charge on the particle that bends up? negative
c) As the charge on the plates is increased, would you expect the bending to increase, decrease, or stay the same? Like charges repel and opposite charges attract, so the sign of the electrical charge on the particle is negative.
d) As the mass of the particle is increased while the speed of the particles remains the same, would you expect the bending to increase, decrease, or stay the same? The greater the magnitude of the charges, the greater the electrostatic repulsion or attraction. As the charge on the plates is increased, the bending will increase.
11. How does Dalton’s atomic theory account for the fact that when 1.000 g of water is decomposed into its elements, 0.111 g of hydrogen and 0889 g of oxygen are obtained regardless of the source of the water? The Law of Definite Composition states that a particular compound always has the same proportion of each element to the every other element.
18. Millikan determined the charge on the electron by studying the static charges on oil drops falling in an electric field. A student carried out this experiment using several oil drops for her measurements and calculated the charges on the drops. She obtained the following data:
Droplet / Calculated Charge (C)A / 1.60 x 10-19
B / 3.15 x 10-19
C / 4.81 x 10-19
D / 6.31 x 10-19
a) What is the significance of the fact that the droplets carried different charges? The droplets carry different total charges because there may be 1,2,3 or more electrons on the droplet.
b) What conclusion can the student draw from these data regarding the charge of the electron? The electronic charge is likely to be the lowest common factor in all the observed charges.
c) What value (and to how many significant figures) should she report for the electronic charge? The average of the apparent electrical charges is 1.59 x 10-19 C
The Modern View of Atomic Structure and Atomic Weights
22. Determine whether each of the following statements is true or false; if false, correct the statement to make it true:
a) The nucleus has most of the mass and comprises very little of the volume of an atom;
b) Every atom of a given element has the same number of protons; True
c) The number of electrons in an atom equals the number of protons in the atom;
d) The protons in the nucleus of the helium atom are held together by a force called the strong nuclear force. True
29. Fill in the gaps in the following table assuming each column represents a neutral atom:
Symbol / 79Br / 55Mn / 112Cd / 222Rn / 207PbProtons / 35 / 25 / 48 / 86 / 82
Neutrons / 44 / 30 / 64 / 136 / 125
Electrons / 35 / 25 / 48 / 86 / 82
Mass number / 79 / 55 / 112 / 222 / 207
33. a) What isotope is used as the standard in establishing the atomic mass scale? Carbon - 12
b) The atomic weight of boron is reported as 10.81, yet no atom of boron has the mass of
10.81 amu. Explain. Atomic weights are really average atomic masses, the sum of the mass of each naturally occurring isotope of an element times its fractional abundance. Each B atom will have the mass of one of the naturally occurring isotopes, while the atomic weight is an average value.
35. Only two isotopes of copper occur naturally, 63Cu (atomic mass = 62.9296 amu; abundance 69.17%) and 65Cu (atomic mass = 64.9278; abundance 30.83%). Calculate the atomic weight (average atomic mass) of copper.
63.55 amu
The Periodic Table and Molecules and Molecular Compounds
42. Locate each of the following elements in the periodic table; indicate whether it is a metal, metalloid, or non-metal; and give the name of the element:
a) Li Lithium (metal)
b) Sc Scandium (metal)
c) Ge Germanium (metalloid)
d) Yb Ytterbium (metal)
e) Mn Manganese (metal)
44. The elements of group 4A show an interesting change in properties with increasing period.
Give the name and chemical symbol of each element in the group, and label it as a nonmetal,
metalloid, or metal. C, carbon, nonmetal; Si, silicon, metalloid; Ge, germanium, metalloid; Sn, tin, metal; Pb, lead, metal
49. Write the empirical formula corresponding to each of the following molecular formulas:
a) Al2Br6 AlBr3
b) C8H10 C4H5
c) C4H8O2 C2H4O2
50. Determine the molecular and empirical formulas of the following:
a) the organic solvent benzene, which has six carbon atoms and six hydrogen atoms; C6H6, CH
b) the compound silicon tetrachloride, which has a silicon atom and four chlorine atoms and is used in the manufacture of computer chips; SiCl4 for both
57. Each of the following elements is capable of forming an ion in chemical reactions.
By referring to the periodic table, predict the charge of the most stable ion of each:
a) Mg2+ b) Al3+ c) K1+ d) S2- e) F1-
Ions and Ionic Compounds
59. Using the periodic table to guide you, predict the formula and name of the compound formed by the following elements:
a) Ga and F GaF3, gallium (III) fluoride
b) Li and H LiF, lithium hydride
c) Al and I AlI3, Aluminum iodide
61. Predict the chemical formula for the ionic compound formed by
a) Ca2+ and Br- CaBr2
b) K+ and CO32- K2CO3
c) Al3+ and C2H3O2- Al(C2H3O2)3
65. Predict whether each of the following compounds is molecular or ionic:
a. B2H6
b. CH3OH
c. LiNO3
d. Sc2O3
Naming Inorganic Compounds and Some Simple Organic Compounds
69. Give the names and charges of the cation and anion in each of the following compounds:
a) CaO calcium, 2+; oxide 2-
b) KClO4 potassium 1+; Chloride 1-
c) Fe(NO3)2 iron, 2+; nitrate 1-
74. Give the chemical formulas for each of the following ionic compounds:
a) sodium phosphate Na3PO4
b) zinc nitrate Zn(NO3)2
c) barium bromate Ba(BrO3)2
d) iron(II) perchlorate Fe(ClO4)2
75. Give the name or chemical formula, as appropriate, for each of the following acids:
a) HBrO3 bromic acid
b) HBr hydrobromic acid
c) H3PO4 phosphoric acid
d) hypochlorous acid HClO
e) iodic acid HIO3
79. Write the chemical formula for each substance mentioned in the following word descriptions.
a) Zinc carbonate can be heated for form zinc oxide and carbon dioxide. Zn(CO3)2, ZnO, CO2
b) On treatment with hydrofluoric acid, silicon dioxide forms silicon tetrafluoride and water.
HF, SiO2, SiF4, H2O
c) Sulfur dioxide reacts with water to form sulfurous acid. SO2, H2O, H2SO3
80. Assume that you encounter the following phrases in your reading.
What is the chemical formula for each substance mentioned?
a) Sodium hydrogen carbonate is used as a deodorant. NaHCO3
b) Calcium hypochlorite is used in some bleaching solutions. Ca(ClO)2
c) Hydrogen cyanide is a very poisonous gas. HCN
81. a) What is a hydrocarbon? A hydrocarbon is a compound composed of only hydrogen and carbon. b) Pentane is the alkane with a chain of five carbon atoms. Write a structural formula for this compound and determine its molecular and empirical formulas. C5H12
84. a) What do ethane and ethanol have in common? Ethane and Ethanol both have 2 Carbons (eth- prefix) B) How does 1-propanol differ from propane? 1-Propanol has an –OH (alcohol group) attached to the chain of 3 carbons that propane does not have.
Chapter 3 “Stoichiometry: Calculations with Chemical Formulas and Equations” Assignments
Chemical Equations
11. Balance the following equations:
a) 2CO(g) + O2(g) à 2CO2(g)
b) N2O5(g) + H2O(l) à 2HNO3(aq)
c) CH4(g) + 4Cl2(g) à CCl4(l) + 4HCl(g)
15. Write balanced chemical equations to correspond to each of the following descriptions:
a) Solid calcium carbide, CaC2, reacts with water to form an aqueous solution of calcium hydroxide and acetylene gas, C2H2. CaC2 + 2H2 O à Ca(OH)2 + C2H2
b) When solid potassium chlorate is heated, it decomposes to form solid potassium chloride and oxygen gas.
2KClO3(s) à 2KCl (s) + 3O2
c) Solid zinc metal reacts with sulfuric acid to form hydrogen gas and an aqueous solution of zinc sulfate.
Zn(s) + H2SO4(aq) à H2 + ZnSO4(aq)
Some Simple Patterns of Chemical Reactivity
17. a) When the metallic element sodium combines with the nonmetallic element bromine, Br2(l), how can you determine the chemical formula of the product? How do you know whether the product is a solid, liquid, or gas at room temperature? Write the balanced chemical equation for the reaction. You need to look at the charges for both ions and write a formula that is neutral as the compound. Since ionic compounds are all solid at room temperature, and sodium bromide is an ionic compound, you can assume that it is a solid. 2Na(s) + Br2(l) à 2NaBr (s)
18. When a compound containing C, H, and O is complete combusted in air, what reactant besides the hydrocarbon is involved in the reaction? Oxygen gas What products are formed? Carbon dioxide and water
19. Write a balanced chemical equation for the reaction that occurs when
a) Mg reacts with Cl2 ; Mg(s) + Cl2(g) à MgCl2(s)
b) Barium carbonate decomposes into barium oxide and carbon dioxide when heated;
BaCO3 à BaO + CO2