MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A 25 g sample of sugar is found to contain 51.4% oxygen by mass. Another 250 g sample of the 1) same sugar is also 51.4% oxygen by mass. This is consistent with the: A) law of multiple proportions. B) first assumption of Dalton's atomic theory. C) second assumption of Dalton's theory. D) law of conservation of mass. E) law of constant composition. 2) When a chemical reaction is carried out in a sealed container, the substances may change in color, temperature or state, but no change in mass is detected. This is evidence of the: A) law of conservation of mass. B) law of definite proportions. C) law of constant composition. D) existance of electrons. E) existance of protons 2) 3) When decomposed chemically, 73.0 grams of a sample of HCl produce 71.0 g of Cl2 and 2.0 g of H2, while 34.0 g of a sample of H2S produce 32.0 g of S and 2.0 g of H2. This is an example of the Law: A) E = mc2 B) of Conservation of Mass C) of Multiple Proportions D) of Definite Proportions E) none of these 3) 4) Choose the INCORRECT statement from those given below. 4) A) Atoms retain their identity during a chemical reaction. B) All atoms of a given element are identical. C) Atoms combine in small, whole-numbered ratios. D) Different ratios of atoms produce different compounds. E) All matter is composed of atoms. 5) A gram sample of magnesium is allowed to burn in g of oxygen gas. The sole product is magnesium oxide. After the reaction, no oxygen remains and g of magnesium oxide has been formed. What mass of magnesium is left unreacted? A) g B) g C) g D) g E) g 5) 6) Dalton's atomic theory is based on several assumptions which are listed below. Which of these assumptions is strictly correct? I) All atoms of the same element are identical. II) Atoms are indivisible and unchangeable. III) Chemical changes are the result of the combination, separation, and rearrangement of atoms. 6)

2 A) II and III are correct. B) I and II are correct. C) I and III are correct. D) I, II, and III are correct. E) III is correct. 7) Choose the INCORRECT statement. 7) A) Objects of like charge repel each other. B) Gamma rays are the same as electrons. C) The Law of Constant Composition is the Law of Definite Proportions. D) Electrons were once known as cathode rays. E) Alpha rays are the same mass as a helium nucleus. 8) Which of the following statements is NOT true? 8) A) J.J. Thomson suggested the "plum pudding" model of the atom. B) Robert Millikan determined the charge on an electron. C) Michael Faraday determined that cathode rays were the fundamental negatively charged particles and called them electrons. D) J.J. Thomson determined the charge-to-mass ratio for electrons. E) Michael Faraday discovered cathode rays. 9) Which of the following would NOT be affected by an electric field? 9) A) Alpha particles B) protons C) Gamma rays D) Beta particles E) electrons 10) Choose the correct statement. 10) A) An electron has 1/1837 the mass of a proton B) Electrons and protons have about the same mass C) The charge of a proton is 1837 times the charge of an electron D) The atomic number is the total number of protons and neutrons in the nucleus E) Neutrons have no charge and no mass 11) Which of the following is a correct feature of the nuclear atom proposed by Rutherford? 11) A) All atoms of an element have the same mass. B) The number of neutrons and electrons in the atom are equal. C) It is like the "plum pudding" model. D) The atom is mostly empty space. E) The majority of alpha particles to strike the foil "bounced back." 12) Beta particles: 12) A) are high speed electrons. B) have a mass of 4 and a charge of +2. C) have the same mass as a neutron.

3 D) are like x-rays. E) are repelled by a positively charged plate. 13) Ernest Rutherford is credited with: I) the nuclear model of the atom. II) the identification of alpha and beta particles. III) the discovery of protons. IV) the prediction of a third, neutral, subatomic particle. A) I and II B) I and III C) I, II, III D) II, III, IV E) I, II, III, IV 13) 14) Choose the INCORRECT statement. 14) A) The atomic number is the proton number. B) The mass number is the number of protons plus neutrons. C) Protons and neutrons are found in the nucleus. D) Gamma rays are bent by magnetic fields as a ray of positive charges. E) Protons and neutrons are close to the same mass. 15) What is the mass number of the most abundant form of oxygen atom? 15) A) B) 32 C) 24 D) 16 E) 8 16) Which of these atoms has the greatest number of neutrons in its nucleus? 16) A) B) C) D) E) Co Si Ni Fe Mn 17) Choose the information that could NOT be found with a mass spectrometer. 17) A) the mass of a proton B) the relative abundance of two isotopes of potassium C) the number of stable isotopes of potassium D) the number of protons in potassium E) the atomic mass of a single isotope of potassium 18) A species which differs in charge from another atom of the same element: I) is called an isotope II) has more or less neutrons III) has lost or gained electrons IV) is called an ion V) has the same number of protons A) I and II B) I and III C) II and IV D) III and IV E) III, IV, V 18) 19) Which of the following statements is true concerning the masses of individual Cl atoms? 19) A) None of the atoms have a mass of u.

4 B) Most of the atoms have a mass of u. C) All atoms have a mass of u. D) All atoms have a mass of 17 u. E) Some of the atoms have a mass of u. 20) A hypothetical element Z has two stable isotopes: Z-46 = u 64.08% Z-51 = u 35.92% What is the average atom weight of the element? A) u B) u C) u D) u E) u 20) 21) A hypothetical element, Z, has two stable isotopes. Z-38 = u 75.68% Z-46 = u 24.32% The element's atomic mass would be closest to which of the elements? A) Ar B) Ca C) Sc D) K E) none of these 21) 22) The atomic weight of chlorine is very close to This means that: 22) A) chlorine occurs with a variable number of protons B) on the average, an atom of chlorine weighs almost 3 times as much as carbon C) a variable number of electrons gives the fractional weight D) the actual weight of a chlorine atom is not known very precisely E) chlorine atoms contain half of a proton 23) An element has 5 stable isotopes. The mass and percentage of each are: % % % % % The element is which of the following? A) Zn B) Ge C) Se D) Ga E) As 23) 24) An element has 5 stable isotopes. The mass and percentage of each are: % % % % % The element is which of the following? A) Y B) Nb C) Sr D) Rb E) Zr 24) 25) Which statement below is true? 25)

5 A) Metals lose electrons to have a positive charge. B) Transition metals can gain 2 or more electrons to become metal ions. C) Metals gain electrons to have a negative charge. D) Metals gain electrons to have a positive charge. E) Nonmetals lose electrons. 26) Groups, or families, on the periodic table are: 26) A) extremely reactive with each other. B) elements which all occur naturally in the same state. C) vertical columns of elements with similar properties. D) named for the first elements in the series; such as "actinides." E) horizontal rows of elements with increasing atomic numbers. 27) Which of the following is NOT a metal? 27) A) bismuth B) radium C) calcium D) selenium E) mercury 28) If we consider 1 atomic mass unit to be equal to grams, calculate the average mass in grams of one Argon atom, atomic number 18. A) g B) g C) g D) g E) g 28) 29) What is the mass in grams of 1 atom of sulfur 29) A) B) C) D) E) ) 31.0 grams of the element phosphorus: 30) A) contain 31.0 ( ) P atoms B) contain P atoms C) contain 31.0 P atoms D) contain 31.0 moles of P E) contain P4 molecules 31) How many atoms are in 5.21 g of arsenic? 31) A) B) C) D)

6 E) ) A cubic centimeter of lead weighs g. How many atoms are in the block? 32) A) B) C) D) E) ) How many moles are represented by Na atoms? 33) A) B) C) D) E) ) The natural abundance of calcium in the earth's crust is 3.4% by mass. How many calcium atoms are present in a 1.50 g sample of the earth's crust? A) B) C) D) E) ) 35) 57.7 g Ni contains how many atoms? 35) A) B) C) D) E) ) How many atoms of silicon are contained in grams? 36) A) atoms B) atoms C) atoms D) atoms E) atoms 37) If the density of lead is g/cm3, how many atoms are in a piece of lead that is 2.00cm wide, 1.00m long, and 2.00 mm thick? A) B) )

7 C) D) E) ) How many atoms of rubidium-85 are in 87.2 g of rubidium. Rubidium-85 is 72.2 % abundant. 38) A) B) C) D) E) ) How many atoms of hydrogen are present in 1.5 lb of hydrogen peroxide, which is 5.93% hydrogen? A) atoms B) atoms C) atoms D) atoms E) atoms 39) 40) How many atoms of sulfur are in 280 g of a 50% H2SO4 solution? 40) A) atoms B) atoms C) atoms D) atoms E) atoms 41) How many Cu atoms are present in a 75.0 cm length of 20-gauge copper wire? A 20-gauge wire has a diameter of in. Copper's density is 8.92 g/cm3. A) B) C) D) E) ) 42) How many atoms of lead are required to cover a 33.0 cm by 45.0 cm area with a sheet of lead that is mm thick? The density of lead is g/cm3. A) B) C) D) E) )

8 43) A g sample of magnesium reacts with g of bromine. The only product is magnesium bromide. If g of magnesium is left unreacted, how much magnesium bromide is formed? A) g B) g C) g D) g E) g 43) 44) What mass of magnesium is necessary to make 10.5 g of magnesium bromide if 1.04 g of magnesium makes 7.88 g of magnesium bromide? A) 1.39 g B) 3.66 g C) 79.9 g D) 7.89 g E) 1.58 g 44) 45) A sample of pure carbon weighing 1.48 g was burned in an excess of air. The mass of carbon dioxide, the sole product, was. In a second experiment, g of carbon dioxide was obtained. What mass of carbon was burned? A) 3.54 g B) g C) 11.6 g D) 42.6 g E) 3.17 g 45) 46) What mass of magnesium oxide is made from g of oxygen is g if magnesium oxide is made from g of oxygen? A) g B) g C) g D) 1.13 g E) 2.53 g 46) 47) Write the symbol for the radioactive isotope phosphorus ) A) B) C) D) E) Ge P P P Ge 48) The total number of neutrons in an is: 48) A) 269 B) 77 C) 192 D) 75 E) ) With mass spectral data the ratio of the mass of was found to be What is the mass of the 14N atom? A) u B) u C) u D) u E) u 49) 50) Which is the proper chemical symbol for tungsten? 50) A) Tm B) Ti C) Te D) Tc E) W 51) The total numbers of neutrons, protons, and electrons in 31P3- are: 51) A) 15 neutrons, 16 protons, 12 electrons B) 15 neutrons, 31 protons, 15 electrons C) 16 neutrons, 15 protons, 18 electrons D) 31 neutrons, 15 protons, 18 electrons E) 16 neutrons, 16 protons, 18 electrons 52) The total numbers of neutrons, protons, and electrons in 35Cl- are: 52) A) 18 neutrons, 17 protons, 18 electrons B) 35 neutrons, 17 protons, 18 electrons

9 C) 17 neutrons, 35 protons, 36 electrons D) 18 neutrons, 17 protons, 16 electrons E) 17 neutrons, 17 protons, 17 electrons 53) The total numbers of neutrons, protons, and electrons in 138Ba2+ are: 53) A) 82 neutrons, 82 protons, 82 electrons B) 138 neutrons, 56 protons, 54 electrons C) 82 neutrons, 56 protons, 58 electrons D) 82 neutrons, 56 protons, 54 electrons E) 56 neutrons, 82 protons, 80 electrons 54) An atom has 13 neutrons and 10 electrons. If it is a cation with a charge of +1, what is its correct symbol? A) B) C) D) E) 54) 55) An atom has 28 neutrons and 21 electrons. If it is a cation with a +3 charge, what is its correct symbol? A) B) C) D) E) 55) 56) An atom has 45 neutrons and 36 electrons. If it is an anion with a -1 charge, which is its correct symbol? A) B) C) D) E) 56) 57) How many protons, neutrons, and electrons are in A) 24 protons, 10 electrons, 12 neutrons B) 12 protons, 10 electrons, 12 neutrons C) 12 protons, 12 electrons, 12 neutrons D) 12 protons, 12 electrons, 24 neutrons E) 10 protons, 12 electrons, 24 neutrons Mg2+? 57) 58) Write the appropriate symbol for the species containing 18 neutrons, 17 protons and 16 electrons. A) B) C) D) E) 58) 59) Which is the proper AZE notion for an ion having 35 protons, 36 electrons and 45 neutrons? 59) A) B) C) D)

10 60) Write the symbol for the most common ion formed by sulfur. 60) A) S+1 B) S-1 C) S+2 D) S-2 E) requires experimental data 61) An isotope with mass number 81 has eleven more neutrons than protons. This is an isotope of what element? A) Tl B) Nb C) Zr D) Br E) Yb 61) 62) The following ratios of masses were obtained with a mass spectrometer: 62) Cl/ F = , F/ C = What is the mass of a Cl atom in atomic mass units? A) u B) u C) u D) u E) u 63) Copper occurs in an isotopic mixture of 69.09% 63Cu (mass = u per atom) and 30.91% 65Cu (mass = u per atom). What is the atomic mass of copper? A) u B) u C) u D) u E) u 63) 64) There are two stable isotopes of supposium (Su). Su-191 = u(27.30%) Su-194 = u(72.70%) Compute the atomic mass of supposium. A) u B) u C) u D) u E) u 64) 65) Which is the more abundant isotope, Cl-35 or Cl-37? 65) A) Cl-37 B) A third unstable isotope is more abundant. C) Cl-35 D) The two isotopes are equal in abundance. E) Cl-17 66) A new element is discovered. It has two isotopes. The relative abundance of the isotopes and their masses are 18% isotope 1, mass u and 82% isotope 2, mass u. What is the atomic mass of the element? A) B) C) D) E) ) 67) The atomic mass of naturally occurring carbon is u. The mass of 13C is u. What is the naturally occurring relative abundance of 13C? A) 1.1% B) 0.011% C) 23% D) 2.2% E) 0.91% 67)

11 68) Rubidium possesses two stable forms and has an average mass of Rb has a mass of 84.9 and a percent abundance of 72.2%. What is the mass of the other form of Rb? A) 87.1 u B) 88.3 u C) 85.7 u D) 86.1 u E) 89.4 u 68) 69) The three naturally occurring isotopes of magnesium are 24Mg ( u, 78.99%), 25Mg ( , 10.00%), and 26Mg. What is the atomic mass of 26Mg? A) u B) u C) u D) u E) u 69) 70) The atomic mass of 19F is How many isotopes of F do you expect? 70) A) one B) two C) three D) five E) four 71) The average atomic mass of B is u. Boron has only two stable forms and 71) What is the natural percent abundance of B? A) 3.8% B) 20% C) 75% D) 80% E) 1.0% 72) Silver possesses two stable forms: 107Ag ( u) and 109Ag ( u). If the average atomic mass of Ag is u, what is the % abundance of 107Ag? A) 50.0% B) 53.8% C) 51.5% D) 46.3% E) 48.5% 72) 73) A certain element contains eleven atoms of mass u for every four atoms of mass u. Compute the average atomic weight of this element. A) u B) u C) u D) u E) u 73) 74) Calculate the percent abundance of the two isotopes of a fictional element, georgium, if it has an average atomic mass of Go u Go u A) Go-290, 62% and Go-292, 38% B) Go-290, 42% and Go-292, 58% C) Go-290, 38% and Go-292, 62% D) Go-290, 58% and Go-292, 42% E) cannot be determined 74) 75) Magnesium has 3 stable isotopes with masses of , , and respectively. Mg-25 is 10.13%. What are the percentages of the other two isotopes? A) 78.9% and 10.9% B) 50% and 50% C) 78.7% and 21.3% D) 83.6% and 16.4% 75)

12 E) 44.9% and 44.9% 76) Lead has 4 stable isotopes with masses of (1.48%), (23.6%), , and respectively. What are the percentages of the last two isotopes? A) 37% and 38% B) 64% and 11% C) 50% and 50% D) 50% and 24% E) 77% and 23% 76) 77) Iodine is a member of the family called: 77) A) actinides B) metalloids C) metals D) noble gasses E) halogens 78) What is the average mass in kilograms of one atom of arsenic? 78) A) kg B) kg C) kg D) kg E) kg 79) What is the mass of a sample containing 1.2 moles of Ni 79) A) 59 g B) 49 g C) 34 g D) 70. g E) 61 g 80) 24.9 g of Mn is equivalent to how many moles of Mn? 80) A) moles B) 2.21 moles C) 1.00 mole D) moles E) moles 81) How many moles of lead are present in a piece of lead with a volume of cm3? The density of Pb is g/cm3. A) B) 11.0 C) D) 6.80 E) ) 82) What is the density (g/cm3) of tin if atoms make a cube 2.31 mm on each side? 82) A) 169 B) 3.28 C) D) E) ) What is the isotopic atomic mass of an isotope if atoms weighs g? 83) A) B) C) D) E)

13 84) What is the atomic weight of an element if 4.00 grams of it contain atoms? 84) A) 80.8 u B) 19.7 u C) 2.02 u D) 8.08 u E) 20.2 u 85) A solution contains 12.5% NaCl by mass. What mass of solution is required to obtain Na atoms? A) 78 g B) g C) 1.2 g D) 95 g E) 30 g 85) 86) A lead cube that is 3.00 cm on each side contains atoms. What is the density of this cube in g/cm3? A) 26.7 B) C) D) 11.4 E) ) 87) Lead-204 has a relative abundance of 1.48%. What size block of lead (in cubic centimeters) will contain A) B) 17.1 C) D) 16.8 E) 194 atoms of lead-204? The density of lead is g/cm3. 87) 88) Lead-206 has a relative abundance of 23.6%. What size block of lead (in cubic centimeters) will contain atoms of lead-206? The density of lead is g/cm3. A) 12.1 B) C) D) 1.07 E) ) 89) What is the thickness in mm of the sheet formed by atoms of 89) lead? The density of lead is g/cm3. A) B) C) D) 2.73 E) ) The age of rocks is sometimes calculated from the measured excess of lead 206 atoms over the normal abundance. The uranium isotope U-238 decays to lead-206. What is the percent abundance of lead-206 if there are 2.58% lead? A) 30.4 B) C) 27.7 D) E) atoms of lead-206 in a 198 g sample of ore that is 90)

14 1) E 2) A 3) B 4) B 5) A 6) E 7) B 8) C 9) C 10) A 11) D 12) A 13) E 14) D 15) D 16) E 17) D 18) E 19) A 20) A 21) A 22) B 23) B 24) E 25) A 26) C

15 27) D 28) E 29) A 30) B 31) B 32) E 33) A 34) A 35) E 36) B 37) D 38) A 39) A 40) C 41) A 42) B 43) B 44) A 45) E 46) D 47) B 48) E 49) D 50) E 51) C 52) A

16 53) D 54) D 55) C 56) C 57) B 58) A 59) A 60) D 61) D 62) B 63) D 64) D 65) C 66) E 67) A 68) A 69) D 70) A 71) D 72) C 73) A 74) C 75) A 76) D 77) E 78) E

17 79) D 80) D 81) A 82) E 83) A 84) A 85) A 86) D 87) B 88) D 89) C 90) A