Chemistry Atoms Molecules and Ions

Chemistry Atoms, Molecules, and Ions 2.1 Multiple-Choice Questions 1) According to history, the concept that all matter is composed of atoms was first proposed by A) the Greek philosopher Democritus, but not widely accepted until modern times. B) Dalton, but not widely accepted until the work of Mendeleev. C) Dalton, but not widely accepted until the work of Einstein. D) Dalton, and widely accepted within a few decades. Answer: A 2) The observation that 15.0 g of hydrogen reacts with 120.0 g of oxygen to form 135.0 g of water is evidence for the law of A) definite proportions. B) energy conservation. C) mass conservation. D) multiple proportions. Answer: C 3) The observation that 4.0 g of hydrogen reacts with 32.0 g of oxygen to form a product with O:H mass ratio = 8:1, and 6.0 g of hydrogen reacts with 48.0 g of oxygen to form the same product with O/H mass ratio = 8:1 is evidence for the law of A) definite proportions. B) energy conservation. C) mass conservation. D) multiple proportions. Answer: A 4) Methane and oxygen react to form carbon dioxide and water. What mass of water is formed if 3.2 g of methane reacts with 12.8 g of oxygen to produce 8.8 g of carbon dioxide? A) 7.2 g B) 8.8 g C) 14.8 g D) 16.0 g Answer: A 5) Sodium metal and water react to form hydrogen and sodium hydroxide. If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was consumed in the reaction? A) 4.68 g B) 5.98 g C) 10.14 g D) 10.66 g Answer: A 6) A sample of pure lithium carbonate contains 18.8% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the first sample? A) 9.40% B) 18.8% C) 37.6% D) 75.2% Answer: B 7) A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 45.0 g of calcium fluoride? A) 2.56 g B) 7.70 g C) 15.0 g D) 23.1 g Answer: D 8) The observation that hydrogen and oxygen can react to form two compounds with different chemical and physical properties, one having an O:H mass ratio = 8:1 and the other having an O:H mass ratio = 16:1 is consistent with the law of A) definite proportions. B) energy conservation. C) mass conservation. D) multiple proportions. Answer: D 9) Which of the following statements is not a postulate of Dalton's atomic theory? A) Each element is characterized by the mass of its atoms. B) Atoms are composed of protons, neutrons, and electrons. C) Chemical reactions only rearrange atomic combinations. D) Elements are composed of atoms. Answer: B 10) Which of the following is a part of Dalton's atomic theory? A) Atoms are rearranged but not changed during a chemical reaction. B) Atoms break down during radioactive decay. C) Atoms contain protons, neutrons, and electrons. D) Isotopes of the same element have different masses. Answer: A 11) Which of the following is not explained by Dalton's atomic theory? A) conservation of mass during a chemical reaction B) the existence of more than one isotope of an element C) the law of definite proportions D) the law of multiple proportions Answer: B 12) Elements A and Q form two compounds, AQ and A2Q3. The mass ratio (mass Q)/(mass A) for AQ is 0.574. What is the mass ratio (mass Q)/(mass A) for A2Q3? A) 0.383 B) 0.861 C) 1.16 D) 2.61 Answer: B 13) Elements A and Q form two compounds, AQ and A2Q. Which of the following must be true? A) (mass Q)/(mass A) is one for AQ, and 1/2 for A2Q. B) (mass Q)/(mass A) for AQ must equal (mass Q)/(mass A) for A2Q. C) (mass Q)/(mass A) for AQ must be 2 times (mass Q)/(mass A) for A2Q. D) (mass Q)/(mass A) for AQ must be 1/2 (mass Q)/(mass A) for A2Q. Answer: C 14) Elements A and Q form two compounds. The ratio (mass Q)/(mass A) for compound one is 0.271 and ratio (mass Q)/(mass A) for compound two is 0.362. If compound one has the chemical formula AQ, what is the chemical formula for compound two? A) A3Q4 B) A2Q3 C) AQ2 D) AQ3 Answer: A 15) The existence of electrons in atoms of all elements was demonstrated by A) Millikan's oil drop experiment. B) Rutherford's gold foil experiment. C) Thomson's cathode ray tube experiment. D) None of these Answer: C Topic: Section 2.3 Atomic Structure: Electrons 16) The charge-to-mass ratio of an electron was established by A) Millikan's oil drop experiment. B) Rutherford's gold foil experiment. C) Thomson's cathode ray tube experiment. D) None of these Answer: C Topic: Section 2.3 Atomic Structure: Electrons 17) The current model of the atom in which essentially all of an atom's mass is contained in a very small nucleus, whereas most of an atom's volume is due to the space in which the atom's electrons move was established by A) Millikan's oil drop experiment. B) Rutherford's gold foil experiment. C) Thomson's cathode ray tube experiment. D) None of these Answer: B Topic: Section 2.4 Atomic Structure: Protons and Neutrons 18) The existence of neutrons in the nucleus of an atom was demonstrated by A) Millikan's oil drop experiment. B) Rutherford's gold foil experiment. C) Thomson's cathode ray tube experiment. D) None of these Answer: D Topic: Section 2.4 Atomic Structure: Protons and Neutrons 19) Most of the alpha particles directed at a thin gold foil in Rutherford's experiment A) bounced directly back from the foil. B) passed directly through the foil undeflected. C) passed through the foil but were deflected at an angle. D) were absorbed by the foil. Answer: B Topic: Section 2.4 Atomic Structure: Protons and Neutrons 20) Which subatomic particle has the smallest mass? A) a proton B) a neutron C) an electron D) an alpha particle Answer: C Topic: Section 2.4 Atomic Structure: Protons and Neutrons 21) A proton is approximately A) 200 times larger than an electron. B) 2000 times larger than an electron. C) 200 times smaller than an electron. D) 2000 times smaller than an electron. Answer: B Topic: Section 2.4 Atomic Structure: Protons and Neutrons 22) The symbol that is usually used to represent atomic number is ________. A) A B) N C) X D) Z Answer: D 23) The mass number of an atom is equal to the number of A) electrons. B) neutrons. C) protons. D) protons plus neutrons. Answer: D 24) Which of the following two atoms are isotopes? A) and B) and C) and D) and Answer: B 25) Which are isotopes? An atom that has an atomic number of 34 and a mass number of 76 is an isotope of an atom that has A) an atomic number of 32 and a mass number of 76. B) an atomic number of 34 and a mass number of 80. C) 42 neutrons and 34 protons. D) 42 protons and 34 neutrons. Answer: B 26) Which of the following represent isotopes? A: [ ] B: [ ] C: [ ] D: [ ] A) A and B B) A and C C) A and D D) C and D Answer: B 27) The isotope represented by is named A) carbon-6 B) carbon-7 C) carbon-13 D) carbon-19 Answer: C 28) Boron-9 can be represented as A) . B) . C) . D) . Answer: B 29) How many protons (p) and neutrons (n) are in an atom of ? A) 38 p, 52 n B) 38 p, 90 n C) 52 p, 38 n D) 90 p, 38 n Answer: A 30) How many protons (p) and neutrons (n) are in an atom of calcium-46? A) 20 p, 26 n B) 20 p, 46 n C) 26 p, 20 n D) 46 p, 60 n Answer: A 31) What is the chemical symbol for an atom that has 29 protons and 36 neutrons? A) Cu B) Kr C) N D) Tb Answer: A 32) How many electrons are in a neutral atom of iodine-131? A) 1 B) 53 C) 54 D) 131 Answer: B 33) How many protons (p), neutrons (n), and electrons (e) are in one atom of ? A) 12 p, 12 n, 12 e B) 12 p, 11 n, 12 e C) 12 p, 11 n, 10 e D) 12 p, 11 n, 14 e Answer: B 34) Identify the chemical symbol of element Q in . A) Br B) Hg C) Pd D) Se Answer: D 35) The atoms of a particular element all have the same number of protons as neutrons. Which of the following must be true? A) The atomic weight must be a whole number. B) The mass number for each atom must equal the atomic weight of the element. C) The mass number must be exactly twice the atomic number for each atom. D) All of these are true. Answer: C 36) The smallest sample of carbon atoms that can be observed with the naked eye has a mass of approximately 2 × 10-8 g. Given that 1 g = 6.02 × 1023 amu, and that carbon has an atomic weight of 12.01 amu, determine the number of carbon atoms present in the sample. A) 1 × 1015 B) 1 × 1016 C) 1 × 1017 D) 6 × 1023 Answer: A 37) An element has two naturally occurring isotopes. One has an abundance of 37.4% and an isotopic mass of 184.953 amu, and the other has an abundance of 62.6% and a mass of 186.956 amu. What is the atomic weight of the element? A) 185.702 amu B) 185.954 amu C) 186.207 amu D) 186.956 amu Answer: C 38) The element antimony has an atomic weight of 121.757 amu and only two naturally-occurring isotopes. One isotope has an abundance of 57.3% and an isotopic mass of 120.904 amu. Based on these data, what is the mass of the other isotope? A) 121.757 amu B) 122.393 amu C) 122.610 amu D) 122.902 amu Answer: D 39) What is the standard isotope that is used to define the number of atoms in a mole? A) 1H B) 12C C) 16O D) 20Ne Answer: B 40) The number of atoms of carbon in 12 g of carbon is closest to . A) 12 B) 1022 C) 1023 D) 1024 Answer: D 41) What is the mass of one atom of the element hydrogen? A) 2.0 g B) 1.0 g C) 3.4 × 10-24 g D) 1.7 × 10-24 g Answer: D 42) One mole of which element has the smallest mass? A) Co B) Cu C) Ni D) Zn Answer: C 43) 24.0 g of which element contains the greatest number of atoms? A) B B) C C) N D) O Answer: A 44) How many moles and how many atoms of zinc are in a sample weighing 34.9 g? A) 0.533 mol, 8.85 ×10-25 atoms B) 0.533 mol, 3.21 ×1023 atoms C) 1.87 mol, 3.10 × 10-24 atoms D) 1.87 mol, 1.13 × 1024 atoms Answer: B 45) Which statement about nuclear reactions is true? A) New elements are never produced in a nuclear reaction. B) Nuclear reactions involve valence electrons. C) The rate of a nuclear reaction is affected by catalysts. D) Tremendous amounts of energy are involved in nuclear reactions. Answer: D 46) The term "nucleons" refers to the number of ________ in the atom. A) neutrons B) protons C) protons and neutrons D) protons, neutrons, and electrons Answer: C 47) The number of nucleons in an atom or ion is the same as the A) atomic number. B) charge on the atom or ion. C) mass number. D) none of these Answer: C 48) The number of nucleons in a nucleus is A) 92. B) 144. C) 236. D) 328. Answer: C 49) The number of neutrons in is A) 26. B) 29. C) 53. D) 55. Answer: B 50) "Isotopes" are atoms with the same number of ________ but different number of ________. A) electrons, protons B) neutrons, protons C) protons, electrons D) protons, neutrons Answer: D 51) The rate of a nuclear reaction can be changed by A) adding a catalyst. B) decreasing the pressure. C) increasing the temperature. D) None of these Answer: D 52) Which of the following statements is not correct when balancing a nuclear equation? I. The mass numbers must be conserved on both sides of the reaction arrow. II. The ionic charges must be conserved on both sides of the reaction arrow. III. The atomic numbers must be conserved on both sides of the reaction arrow. IV. The elements must be the same on both sides of the reaction arrow. A) II only B) II and III C) I and III D) II and IV Answer: D Topic: Section 2.8 Radioactivity 53) An alpha particle is A) . B) . C) . D) . Answer: D Topic: Section 2.8 Radioactivity 54) When a substance decays by alpha radiation, the mass number of the nucleus ________ and the atomic number ________. A) increases by 4, increases by 2 B) reduces by 4, reduces by 2 C) increases by 2, increases by 4 D) reduces by 2, reduces by 4 Answer: B Topic: Section 2.8 Radioactivity 55) The nuclear decay process that involves the particle having the greatest mass is ________ emission. A) alpha B) beta C) gamma D) positron Answer: A Topic: Section 2.8 Radioactivity 56) A beta particle is A) . B) . C) . D) . Answer: A Topic: Section 2.8 Radioactivity 57) When a substance decays by beta emission, the mass number of the nucleus ________ and the atomic number ________. A) decreases by 1, remains the same B) increases by 1, remains the same C) remains the same, decreases by 1 D) remains the same, increases by 1 Answer: D Topic: Section 2.8 Radioactivity 58) Beta decay of 24Na produces a beta particle and A) 20F. B) 23Na. C) 24Ne. D) 24Mg. Answer: D Topic: Section 2.8 Radioactivity 59) Which of the following statements about gamma radiation is false? A) It almost always accompanies alpha or beta emission. B) It is a mechanism to release excess energy in the nucleus. C) Gamma rays are high energy photons. D) The mass number decreases by one with each gamma emitted. Answer: D Topic: Section 2.8 Radioactivity 60) Gamma radiation can be described as A) a helium nucleus. B) a negatively charged free electron. C) high energy electromagnetic radiation. D) a positively charged free electron. Answer: C Topic: Section 2.8 Radioactivity 61) A positron is A) . B) . C) . D) . Answer: C Topic: Section 2.8 Radioactivity 62) Positron emission changes the atomic number of an element by A) -2. B) -1. C) +1. D) +2. Answer: B Topic: Section 2.8 Radioactivity 63) Which of the following statements about positrons is false? A) The positron has same mass as an electron. B) A positron is ejected from the nucleus during the conversion of a proton into a neutron. C) A positron is a positive electron. D) When positron emission occurs, the atomic number of the nucleus increases. Answer: D Topic: Section 2.8 Radioactivity 64) The nuclear transformation potassium-40 argon-40 + ? is classified as A) alpha emission. B) beta emission. C) electron capture. D) positron emission. Answer: D Topic: Section 2.8 Radioactivity 65) Which of the following statements about electron capture is false? A) The electron is used to convert a proton to a neutron. B) The electron involved is most likely an outer shell valence electron. C) In electron capture decay, the atomic number decreases by one. D) In electron capture decay, the mass number remains unchanged. Answer: B Topic: Section 2.8 Radioactivity 66) Which one of the following processes does not result in transmutation to another element? A) alpha emission B) beta emission C) electron capture D) gamma emission Answer: D Topic: Section 2.8 Radioactivity 67) Which of the following decay processes give a product nuclide whose atomic number is one less than the starting nuclide? A) alpha decay B) beta decay and positron decay C) gamma decay and beta decay D) positron decay and electron capture Answer: D Topic: Section 2.8 Radioactivity 68) Which reaction below represents decay by positron emission? A) ? + B) ? + C) ? + D) ? + Answer: B Topic: Section 2.8 Radioactivity 69) Which reaction below represents decay by alpha emission? A) ? + B) ? + C) ? p + D) ? n + Answer: A Topic: Section 2.8 Radioactivity 70) Which reaction below represents decay by electron capture? A) + ? B) + ? C) + ? D) + ? Answer: D Topic: Section 2.8 Radioactivity 71) In addition to a beta particle, what is the other product of beta decay of ? A) B) C) D) Answer: C Topic: Section 2.8 Radioactivity 72) Tritium, , is formed in the upper atmosphere when captures a neutron and then decays. What is the other product of this reaction? A) B) C) D) Answer: B Topic: Section 2.8 Radioactivity 73) When more than 3000 known nuclides are plotted on a neutron/proton grid they make up a group called A) the "island of stability." B) the "peninsula of nuclear stability." C) the "sea of instability." D) none of these Answer: B Topic: Section 2.9 Nuclear Stability 74) Which is the only element that contains more protons than neutrons in its most abundant stable isotope? A) boron B) carbon C) hydrogen D) mercury Answer: C Topic: Section 2.9 Nuclear Stability 75) As the atomic number of the elements increases, the ratio of neutrons to protons in stable nuclei A) decreases. B) stays the same. C) increases. D) is unrelated to stability. Answer: C Topic: Section 2.9 Nuclear Stability 76) Which one of the following statements about isotopes is false? A) The ratio of neutrons to protons is about 1:1 for elements lighter than Ca. B) The ratio of neutrons to protons is > 1:1 for elements heavier than Ca. C) Nonradioactive isotopes generally have an odd number of neutrons. D) All isotopes beyond 209Bi are radioactive. Answer: C Topic: Section 2.9 Nuclear Stability 77) Which one of the following combinations of neutrons/protons results in the lowest number of nonradioactive (stable) isotopes? A) even number protons/even number neutrons B) even number protons/odd number neutrons C) odd number protons/even number neutrons D) odd number protons/odd number neutrons Answer: D Topic: Section 2.9 Nuclear Stability 78) Which of the following elements would you expect to have the largest number of stable isotopes? Element number: A) 48 B) 49 C) 50 D) 51 Answer: C Topic: Section 2.9 Nuclear Stability 79) Which of the following elements would be expected to be particularly stable? A) B) C) D) Answer: A Topic: Section 2.9 Nuclear Stability 80) Which process decreases the neutron/proton ratio? A) alpha emission B) beta emission C) electron capture D) positron emission Answer: B Topic: Section 2.9 Nuclear Stability 81) A radioisotope has a neutron/proton ratio which is too low. Which of the following processes will not occur for such a nucleus? A) alpha emission B) beta emission C) electron capture D) positron emission Answer: B Topic: Section 2.9 Nuclear Stability 82) A radioisotope which is neutron poor and very heavy is most likely to decay by A) alpha emission, electron capture, or positron emission. B) only alpha emission. C) only electron capture. D) only positron emission. Answer: A Topic: Section 2.9 Nuclear Stability 83) Which of the following nuclides is most likely to undergo beta decay? A) B) C) D) Answer: D Topic: Section 2.9 Nuclear Stability 84) Which of the following nuclides is most likely to decay by electron capture? A) B) C) D) Answer: A Topic: Section 2.9 Nuclear Stability 85) What nuclide is formed when undergoes a portion of the decay series: alpha, beta, beta, alpha, alpha, alpha. A) B) C) D) Answer: B Topic: Section 2.9 Nuclear Stability 86) When decays in a 5-step series the product is . How many alpha and beta particles are emitted in the decay series? A) 2 ?, 3 ?- B) 3 ?, 2 ?- C) 4 ?, 1 ?- D) 1 ?, 4 ?- Answer: B Topic: Section 2.9 Nuclear Stability 87) A banana split is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: C 88) Apple juice is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: D 89) Gold is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: B 90) Carbon dioxide is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: A 91) Steel is galvanized by giving it a surface coating of zinc. Galvanized steel is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: C 92) How many electrons are in the ion, Zn2+? A) 28 B) 30 C) 32 D) 65 Answer: A 93) How many electrons are in the ion, P3-? A) 12 B) 18 C) 28 D) 34 Answer: B 94) In which of the following sets do all species have the same number of electrons? A) Br-, Kr, Sr2+ B) C, N3-, O2- C) Mg2+, Sr2+, Ba2+ D) O, O2-, O2+ Answer: A 95) In which of the following sets do all species have the same number of protons? A) Br-, Kr, Sr2+ B) C, N3-, O2- C) Mg2+, Sr2+, Ba2+ D) O, O2-, O2+ Answer: D 96) What is the identity of element Q if the ion Q2+ contains 10 electrons? A) C B) O C) Ne D) Mg Answer: D 97) How many electrons are in the ion, CO32-? A) 16 B) 28 C) 30 D) 32 Answer: D 98) In which set do all elements tend to form cations in binary ionic compounds? A) Li, B, O B) Mg, Cr, Pb C) N, As, Bi D) O, F, Cl Answer: B 99) In which set do all elements tend to form anions in binary ionic compounds? A) C, S, Pb B) K, Fe, Br C) Li, Na, K D) N, O, I Answer: D 100) What is the most likely charge on an ion of phosphorus, P? A) 5- B) 3- C) 3+ D) 5+ Answer: B 101) Which element can form more than one kind of monatomic ion? A) Ca B) Cl C) Cr D) Cs Answer: C 102) Which element can form more than one kind of monatomic ion? A) S B) Se C) Sn D) Sr Answer: C 103) What type of bonding is found in the compound PCl5? A) covalent bonding B) hydrogen bonding C) ionic bonding D) metallic bonding Answer: A 104) Which one of the following compounds contains ionic bonds? A) CaO B) HF C) NI3 D) SiO2 Answer: A 105) Which of the following is the correct chemical formula for a molecule of bromine? A) Br B) Br- C) Br+ D) Br2 Answer: D 106) Which of the compounds, Li3P, PH3, C2H6, IBr3, are ionic compounds? A) only C2H6 B) only Li3P C) Li3P and PH3 D) PH3, C2H6, and IBr3 Answer: B 107) Which of the compounds, C3H8, MgCl2, Zn(NO3)2, OCl2, are expected to exist as molecules? A) only C3H8 B) C3H8 and OCl2 C) C3H8, Zn(NO3)2, and OCl2 D) MgCl2 and Zn(NO3)2 Answer: B 108) Which of the species below has 28 protons and 26 electrons? A) Fe2+ B) Ni2+ C) D) Answer: B 109) Which of the following elements has the least tendency to form an ion? A) Ca B) K C) Kr D) Se Answer: C 110) Butyric acid has the structural formula given below. What is the molecular or chemical formula for butyric acid? A) CHO B) C2H4O C) C4H8O2 D) C5H8O3 Answer: C 111) The solid compound, Na2CO3, contains A) Na+, C4+, and O2- ions. B) Na+ ions and CO32-ions. C) Na2+ and CO32- ions. D) Na2CO3 molecules. Answer: B 112) Which of the following statements concerning ionic compounds is true? A) Essentially all ionic compounds are solids at room temperature and pressure. B) Ionic compounds do not contain any covalent bonds. C) Ionic compounds contain the same number of positive ions as negative ions. D) The chemical formula for an ionic compound must show a nonzero net charge. Answer: A 113) The gas Freon-11, CCl3F, contains A) C4+, Cl-, and F- ions. B) C4+, Cl3-, and F- ions. C) C4+ and Cl3F4- ions. D) CCl3F molecules. Answer: D 114) The definitive distinction between ionic bonding and covalent bonding is that A) ionic bonding involves a sharing of electrons and covalent bonding involves a transfer of electrons. B) ionic bonding involves a transfer of electrons and covalent bonding involves a sharing of electrons. C) ionic bonding requires two nonmetals and covalent bonding requires a metal and a nonmetal. D) covalent bonding requires two nonmetals and ionic bonding requires a metal and a nonmetal. Answer: B 115) What is the chemical formula for iron(II) phosphate? A) Fe2P B) Fe2PO4 C) Fe3P2 D) Fe3(PO4)2 Answer: D 116) What is the charge on the Cr in the ionic compound Cr2O3? A) 2- B) 1+ C) 2+ D) 3+ Answer: D 117) Li2S is named A) lithium disulfide. B) lithium sulfide. C) lithium(II) sulfide. D) lithium sulfur. Answer: B 118) What is the chemical formula for strontium hydroxide? A) SrH2 B) SrOH C) SrOH2 D) Sr(OH)2 Answer: D 119) What is the chemical formula for strontium hydride? A) SrH2 B) SrOH C) SrOH2 D) Sr(OH)2 Answer: A 120) The formula for dinitrogen trioxide is A) N(OH)3. B) (NO3)2. C) N2O3. D) N3O2. Answer: C 121) The chemical formula for the sulfite ion is A) S-. B) S2-. C) SO32-. D) SO42-. Answer: C 122) The chemical formula for potassium peroxide is A) KOH. B) KO2. C) K2O. D) K2O2. Answer: D 123) The compound, Cu(ClO3)2, is named A) copper chlorate(II). B) copper(I) chlorate. C) copper(I) chlorate(II). D) copper(II) chlorate. Answer: D 124) By analogy with the oxoanions of sulfur, H2TeO3 would be named A) hydrotellurous acid. B) pertelluric acid. C) telluric acid. D) tellurous acid. Answer: D 125) The ions ClO4-, ClO3-, ClO2-, and ClO- are named respectively A) hypochlorate, chlorate, chlorite, perchlorite. B) hypochlorite, chlorite, chlorate, perchlorate. C) perchlorate, chlorate, chlorite, hypochlorite. D) perchlorite, chlorite, chlorate, hypochlorate. Answer: C 126) The compound, NO2, is named A) nitrate. B) nitrite. C) nitrogen dioxide. D) nitrogen(IV) oxide. Answer: C 127) The ion NO2- is named A) nitrate ion. B) nitrite ion. C) nitrogen dioxide ion. D) nitrogen(II) oxide ion. Answer: B 128) The chemical formula for calcium nitride is A) Ca(NO3)2. B) Ca(NO2)2. C) Ca3N2. D) CaN2. Answer: C 129) The thiosulfate ion is A) HS-. B) HSO42-. C) SO52-. D) S2O32-. Answer: D 130) KH2PO4 is A) hydropotassium phosphate. B) potassium dihydrogen phosphate. C) potassium diphosphate. D) potassium hydrogen(II) phosphate. Answer: B 131) What are the names of the ions Ba2+, Sn2+, and Se2-? A) barium, tin, and selenium B) barium, tin(II), and selenide C) barium(II), tin(II), and selenium(II-) D) barous, stannous, and selenide Answer: B 132) Which of the above drawings represents a pure element? A) drawing (a) B) drawing (b) C) drawing (c) Answer: B 133) Which of the above drawings represents a pure compound? A) drawing (a) B) drawing (b) C) drawing (c) Answer: A 134) Which of the above drawings represents a mixture? A) drawing (a) B) drawing (b) C) drawing (c) Answer: C 135) Which of the following drawings represents a collection of acetylene (C2H2) molecules? The shaded spheres represent carbon atoms and the unshaded spheres represent hydrogen atoms. A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: C 136) If unshaded spheres represent sulfur atoms and shaded spheres represent oxygen atoms, which of the following drawings depicts a collection of sulfur trioxide molecules? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: D 137) Which of the above drawings represents an Ar atom? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: B 138) Which of the above drawings represents a Cl- ion? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: A 139) Which of the above drawings represents a Ca2+ ion? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: D 140) Which of the above drawings represents a K+ ion? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: C 141) Assume that the mixture of substances in drawing (1) undergoes a chemical reaction. Which of the drawings (2)-(4) represents a product mixture that is consistent with the law of mass conservation? A) drawing (2) B) drawing (3) C) drawing (4) Answer: B 142) Assume that the mixture of substances in drawing (1) undergoes a chemical reaction. Which of the drawings (2)-(4) represents a product mixture that is consistent with the law of mass conservation? A) drawing (2) B) drawing (3) C) drawing (4) Answer: C 143) Which of the following drawings depicts a chemical reaction consistent with Dalton's atomic theory? A) drawing a) B) drawing b) C) drawing c) D) drawing d) Answer: A 144) Which of the following drawings depicts a chemical reaction consistent with Dalton's atomic theory? A) drawing a) B) drawing b) C) drawing c) D) drawing d) Answer: D 145) If shaded and unshaded spheres represent atoms of different elements, as shown in drawing (1), which drawings (2)-(4) represent the law of multiple proportions? A) only drawings (2) and (3) B) only drawings (2) and (4) C) only drawings (3) and (4) D) drawings (2), (3), and (4) Answer: C 146) If shaded and unshaded spheres represent atoms of different elements, as shown in drawing (1), which drawings (2)-(4) represent the law of multiple proportions? A) only drawings (2) and (3) B) only drawings (2) and (4) C) only drawings (3) and (4) D) drawings (2), (3), and (4) Answer: B 147) If shaded and unshaded spheres represent atoms of different elements, as shown in drawing (1), which drawings (2)-(4) represent the law of multiple proportions? A) only drawings (2) and (3) B) only drawings (2) and (4) C) only drawings (3) and (4) D) drawings (2), (3), and (4) Answer: A 148) If shaded and unshaded spheres represent atoms of different elements, as shown in drawing (1), which drawings (2)-(4) represent the law of multiple proportions? A) only drawings (2) and (3) B) only drawings (2) and (4) C) only drawings (3) and (4) D) drawings (2), (3), and (4) Answer: D 149) If shaded and unshaded spheres represent atoms of different elements, as shown in drawing (1), which combination of drawings (2)-(4) represent the law of multiple proportions? A) only drawings (2) and (3) B) only drawings (2) and (4) C) only drawings (3) and (4) D) drawings (2), (3), and (4) Answer: D 150) Which of the following figures represents ? Unshaded spheres represent neutrons and shaded spheres represent protons. A) figure (1) B) figure (2) C) figure (3) D) figure (4) Answer: B 151) Which of the following figures represents ? Unshaded spheres represent neutrons and shaded spheres represent protons. A) figure (1) B) figure (2) C) figure (3) D) figure (4) Answer: D 152) Which of the following figures represents ? Unshaded spheres represent neutrons and shaded spheres represent protons. A) figure (1) B) figure (2) C) figure (3) D) figure (4) Answer: A 153) Tell the type of decay process occurring in the following nuclear reaction. A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: D 154) Tell the type of decay process occurring in the following nuclear reaction. A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: D 155) Tell the type of decay process occurring in the following nuclear reaction. A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: B 156) Tell the type of decay process occurring in the following nuclear reaction. A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: B 157) Tell the type of decay process occurring in the following nuclear reaction. A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: A 158) Tell the type of decay process occurring in the following nuclear reaction. A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: A 159) What kind of decay process is occurring in the decay of isotope A to isotope B in the figure shown above? A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: A 160) What kind of decay process is occurring in the decay of isotope B to isotope C in the figure shown above? A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: B 161) What kind of decay process is occurring in the decay of isotope C to isotope D in the figure shown above? A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: B 162) What kind of decay process is occurring in the decay of isotope D to isotope E in the figure shown above? A) ? emission B) ? emission C) ? emission D) electron capture or positron emission Answer: A 163) Give the molecular formula corresponding to the following ball-and-stick molecular representation of vitamin C (ascorbic acid) (gray = C, unshaded = H, black = O). In writing the formula, list the atoms in alphabetical order. A) CHO B) C3H4O3 C) C6H4O6 D) C6H8O6 Answer: D 164) Give the molecular formula corresponding to the following ball-and-stick molecular representation of naphthalene (gray = C, unshaded = H). In writing the formula, list the atoms in alphabetical order. A) CH B) C5H4 C) C10H8 D) C10H10 Answer: C 165) If shaded and unshaded spheres represent atoms of different elements, which of the above drawings most likely represents an ionic compound at room temperature and a pressure of 1 atm? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: D 166) If shaded and unshaded spheres represent atoms of different elements, which of the above drawings most likely represents a molecular compound at room temperature and a pressure of 1 atm? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: B 167) If shaded and unshaded spheres represent atoms of different elements, which of the above drawings most likely represents an ionic compound at room temperature and a pressure of 1 atm? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: A 168) If shaded and unshaded spheres represent atoms of different elements, which of the above drawings most likely represents a molecular compound at room temperature and a pressure of 1 atm? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: C Use the periodic table below to answer the following questions. 169) Which elements commonly form anions? A) A and B B) A and C C) B and D D) C and D Answer: D 170) Which elements commonly form cations? A) A and B B) A and C C) B and D D) C and D Answer: A 171) Which elements commonly form covalent bonds? A) A and B B) A and C C) B and D D) C and D Answer: D In the following drawings, shaded spheres represent cations and unshaded spheres represent anions. 172) Which drawing represents the ionic compound Mg3(PO4)2? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: D 173) Which drawing represents the ionic compound Na2CO3? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: B 174) Which drawing represents the ionic compound CaCl2? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: C 175) Which drawing represents the ionic compound KNO3? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: A 176) Which drawing represents the ionic compound NH4ClO4? A) drawing (a) B) drawing (b) C) drawing (c) D) drawing (d) Answer: A Use the periodic table below to answer the following questions. 177) Which is the correct formula of the binary fluoride of element A? A) AF2 B) AF3 C) AF5 D) AF6 Answer: A 178) Which is the correct formula of the binary fluoride of element B? A) BF2 B) BF3 C) BF5 D) BF6 Answer: B 179) In which pair are both formulas of binary fluorides of element C correct? A) CF2 and CF3 B) CF2 and CF6 C) CF3 and CF5 D) CF5 and CF6 Answer: C 180) In which pair are both formulas of binary fluorides of element D correct? A) DF2 and DF3 B) DF2 and DF6 C) DF3 and DF5 D) DF5 and DF6 Answer: B 181) Which is most likely to form a binary oxide with the formula MO (where M = element A, B, C, or D)? A) element A B) element B C) element C D) element D Answer: A 182) Which is most likely to form a binary oxide with the formula MO3 (where M = element A, B, C, or D)? A) element A B) element B C) element C D) element D Answer: D 183) Which is most likely to form a binary oxide with the formula M2O3 (where M = element A, B, C, or D)? A) element A B) element B C) element C D) element D Answer: B 184) Which is most likely to form a binary oxide with the formula M4O10 (where M = element A, B, C, or D)? A) element A B) element B C) element C D) element D Answer: C 2.2 Algorithmic Questions 1) Methane and oxygen react to form carbon dioxide and water. What mass of water is formed if 0.80 g of methane reacts with 3.2 g of oxygen to produce 2.2 g of carbon dioxide? A) 1.8 g B) 2.2 g C) 3.7 g D) 4.0 g Answer: A 2) Sodium metal and water react to form hydrogen and sodium hydroxide. If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was involved in the reaction? A) 4.68 g B) 5.98 g C) 10.14 g D) 10.66 g Answer: A 3) A sample of pure lithium carbonate contains 18.8.4% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the first sample? A) 9.40% B) 18.8% C) 37.6% D) 75.2% Answer: B 4) A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 40.0 g of calcium fluoride? A) 2.27 g B) 7.70 g C) 15.0 g D) 20.5 g Answer: D 5) Elements A and Q form two compounds, AQ and A2Q3. The mass ratio (mass Q)/(mass A) for AQ is 0. 291. What is the mass ratio (mass Q)/(mass A) for A2Q3? A) 0. 194 B) 0. 436 C) 2.29 D) 5.15 Answer: B 6) Which are isotopes? An atom that has an atomic number of 20 and a mass number of 42 is an isotope of an atom that has A) an atomic number of 21 and a mass number of 42. B) an atomic number of 20 and a mass number of 40. C) 22 neutrons and 20 protons. D) 22 protons and 20 neutrons. Answer: B 7) Which of the following represent isotopes? A: [ ] B: [ ] C: [ ] D: [ ] A) A and B B) A and C C) A and D D) C and D Answer: B 8) How many protons (p) and neutrons (n) are in an atom of ? A) 38 p, 52 n B) 38 p, 90 n C) 52 p, 38 n D) 90 p, 38 n Answer: A 9) How many protons (p) and neutrons (n) are in an atom of barium-130? A) 56 p, 74 n B) 56 p, 130 n C) 74 p, 56 n D) 130 p, 56 n Answer: A 10) What is the element symbol for an atom that has 5 protons and 6 neutrons? A) B B) C C) H D) Na Answer: A 11) How many electrons are in a neutral atom of bromine-81? A) 1 B) 35 C) 36 D) 81 Answer: B 12) Identify the chemical symbol of element Q in . A) Br B) Hg C) Pd D) Se Answer: D 13) The number of nucleons in a nucleus is A) 90. B) 144. C) 234. D) 324. Answer: C 14) Beta decay of 32P produces a beta particle and A) 28Al. B) 31P. C) 32Si. D) 32S. Answer: D Topic: Section 2.8 Radioactivity 15) In addition to a beta particle, what is the other product of beta decay of ? A) B) C) D) Answer: C Topic: Section 2.8 Radioactivity 16) Which of the following elements would be expected to be particularly stable? A) B) C) D) Answer: A Topic: Section 2.9 Nuclear Stability 17) Which of the following nuclides is most likely to undergo beta decay? A) B) C) D) Answer: D Topic: Section 2.9 Nuclear Stability 18) Which nuclide below is most likely to decay by electron capture? A) B) C) D) Answer: A Topic: Section 2.9 Nuclear Stability 19) Crude oil is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: C 20) Gasoline is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: D 21) Gold is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: B 22) Ammonia is an example of A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. Answer: A 23) In which set do all elements tend to form cations in binary ionic compounds? A) K, Ga, O B) Sr, Ni, Hg C) N, P, Bi D) O, Br, I Answer: B 24) How many electrons are in the ion, Cu2+? A) 27 B) 29 C) 31 D) 64 Answer: A 25) How many electrons are in the ion, P3-? A) 12 B) 18 C) 28 D) 34 Answer: B 26) In which of the following sets do all species have the same number of electrons? A) F-, Ne, Mg2+ B) Ge, Se2-, Br- C) K+, Rb+, Cs+ D) Br, Br-, Br+ Answer: A 27) In which of the following sets do all species have the same number of protons? A) F-, Ne, Mg2+ B) Ge, Se2-, Br- C) K+, Rb+, Cs+ D) Br, Br-, Br+ Answer: D 28) What is the identity of element Q if the ion Q2+ contains 10 electrons? A) C B) O C) Ne D) Mg Answer: D 29) How many electrons are in the ion, PO43-? A) 26 B) 44 C) 47 D) 50 Answer: D 30) In which set do all elements tend to form anions in binary ionic compounds? A) C, S, Pb B) K, Fe, Br C) Li, Na, K D) N, O, I Answer: D 31) What type of bonding is found in the compound O F2? A) covalent bonding B) hydrogen bonding C) ionic bonding D) metallic bonding Answer: A 32) Which one of the following compounds contains ionic bonds? A) SrO B) H Br C) P Br3 D) SiO2 Answer: A 33) Which of the following is the correct chemical formula for a molecule of astatine? A) At B) At- C) At+ D) At2 Answer: D 34) Which of the compounds, Li3N, NH3, C3H8, IF3 are ionic compounds? A) only C3H8 B) only Li3N C) Li3N and N H3 D) N H3, C3H8, and I F3 Answer: B 35) Which of the compounds CH4, SrCl2, Cr(NO3)3, XeF2 are expected to exist as molecules? A) only CH4 B) CH4 and Xe F2 C) CH4, Cr(NO3)2, and Xe F2 D) SrCl2 and Cr(NO3)2 Answer: B 36) Which of the following elements has the least tendency to form an ion? A) Ca B) K C) Kr D) Se Answer: C 37) The solid compound, Mg(NO3)2, contains A) Mg2+, N5+, and O2- ions. B) Mg2+ ions and (NO32- ions. C) Mg 2+ and (NO32- ions. D) Mg(NO3)2 molecules. Answer: B 38) What is the chemical formula for iron( III) sulfate? A) Fe3S B) Fe3SO4 C) Fe2S3 D) Fe2( SO4)3 Answer: D 39) What is the charge on the Cr ions in Cr2O3? A) 2- B) 1+ C) 2+ D) 3+ Answer: D 40) Rb2S is named A) rubidium disulfide. B) rubidium sulfide. C) rubidium(II) sulfide. D) rubidium sulfur. Answer: B 41) What is the chemical formula for calcium hydroxide? A) CaH2 B) CaOH C) CaOH2 D) Ca(OH)2 Answer: D 42) What is the chemical formula for magnesium hydride? A) MgH2 B) MgOH C) MgOH2 D) Mg(OH)2 Answer: A 43) An aqueous solution of H2S is named A) hydrosulfuric acid. B) hydrosulfurous acid. C) sulfuric acid. D) sulfurous acid. Answer: A 44) The chemical formula for the sulfite ion is A) S-. B) S 2-. C) SO32-. D) SO42-. Answer: C 45) The chemical formula for lithium peroxide is A) LiOH. B) LiO2. C) Li2O. D) Li2O2. Answer: D 46) The compound, Cu( I O3 )2, is named A) copper iodate(II). B) copper(I) iodate. C) copper(I) iodate(II). D) copper(II) iodate. Answer: D 47) The compound, SO3, is named A) sulfate. B) sulfite. C) sulfur trioxide. D) sulfur ( VI) oxide. Answer: C 48) The ion, IO2-, is named A) iodate ion. B) iodite ion. C) iodine dioxide ion. D) iodine(II) oxide ion. Answer: B 49) The chemical formula for nitrous acid is A) H3N(aq). B) H NO2(aq). C) H NO3(aq). D) H2N2O6(aq). Answer: B 50) The chemical formula for calcium nitride is A) Ca(NO3)2. B) Ca(NO2)2. C) Ca3N2. D) CaN2. Answer: C 2.3 Short Answer Questions 1) In the reaction HBr + NaOH ? H2O + NaBr, If 81 g HBr react with 40 g of NaOH to produce 18 g of H2O, the number of grams of NaBr produced is ________. Answer: 103 g 2) According to the law of multiple proportions, if 12 g of carbon combine with 16 g of oxygen to form CO, the number of grams of carbon that combine with 16 g of oxygen in the formation of CO2 is ________. Answer: 6 g 3) The charge to mass ratio of an electron was determined from Rutherford’s cathode-ray tube experiment to be 1.759 × 108 C/g and the charge on a single electron was determined from the Millikan oil drop experiment to be 1.602 × 10-19 C, so the mass of a single electron is ________. Answer: 9.11 × 10-28 g Topic: Section 2.3 Atomic Structure: Electrons 4) The subatomic particles contained in the nucleus of an atom are ________ and ________. Answer: protons, neutrons Topic: Section 2.4 Atomic Structure: Protons and Neutrons 5) Atoms of the same element always have the same number of ________ in their nuclei. Answer: protons 6) Isotopes have the same number of ________ but different numbers of ________ in their nuclei. Answer: protons, neutrons 7) The symbol of the isotope having Z = 88 and A = 226 is ________. Answer: 8) The symbol for technetium-98 is ________. Answer: 9) The number of neutrons in a neutral atom of uranium-238 is ________. Answer: 146 10) A neutral atom with atomic number 5 and mass number 11 contains ________ electrons. Answer: 5 11) Chlorine has two common isotopes, chlorine-35 and chlorine-37, and an atomic mass of 35.45 amu. The natural abundance of chlorine-35 is ________ (greater than, less than, the same as) the natural abundance of chlorine-37. Answer: greater than 12) The number of atoms in 23 g of Na is ________ (greater than, less than, the same as) the number of atoms in 12 g of C. Answer: the same as 13) To the nearest whole number, the number of grams of Ba in 3.25 mol of Ba is ________. Answer: 446 g 14) The number of moles of Li in 34.7 g Li is ________. Answer: 5.00 mol 15) The number of protons, neutrons, and total nucleons in are ________, ________, and ________, respectively. Answer: 44, 62, 106 16) The missing reactant in the nuclear reaction ? ? + is ________. Answer: 17) In a nuclear reaction, the symbol for a beta particle is ________. Answer: or ?- Topic: Section 2.8 Radioactivity 18) In a nuclear reaction is the symbol for ________. Answer: an alpha particle Topic: Section 2.8 Radioactivity 19) undergoes alpha decay producing one alpha particle and a single nuclide. To balance the equation, ________ and ________ must be added to the right side of the equation below. ? ? + ? Answer: , Topic: Section 2.8 Radioactivity 20) In an electron capture reaction a proton is converted into a ________. Answer: neutron Topic: Section 2.8 Radioactivity 21) Nuclei that are in the band of stability have a neutron/proton ratio ________ (equal to, greater than, less than) 1:1. Answer: greater than Topic: Section 2.9 Nuclear Stability 22) 10% saline solution (sodium chloride dissolved in water) is an example of a ________ mixture. Answer: homogeneous 23) The number of electrons in the ion Ca2+ is ________. Answer: 18 24) The number of electrons in the ion C4– is ________. Answer: 10 25) The bonding in MgO is ________, whereas the bonding in CO is ________. Answer: ionic, covalent 26) Phosphate ion has the formula ________. Answer: PO43– 27) The formula of iron(III) oxide contains ________ iron(III) and ________ oxide ions. Answer: 2, 3