991_3rd_Exam_991215
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) What is the frequency of radiation with a wavelength of 440. nm? ( C = 3.0 × 108 m/s ) A) 2.02 × 10-11 s-1
B) 6.81 × 1014 s-1 C) 1.51 × 10-27 s-1 D) 4.95 × 10-12 s-1
E) 6.81 × 105 s-1 Answer: B
2) The existence of discrete (quantized) energy levels in an atom may be inferred from:
A) atomic line spectra
B) diffraction of electrons by crystals C) visible spectrum
D) X-ray diffraction by crystals
E) experiments on the photoelectric effect Answer: A
3) The photoelectric effect:
A) was discovered by Max Planck
B) results in a beam of electrons which increases in number, but not velocity, as the wavelength of incident light decreases
C) contradicted the view that light energy was dependent upon intensity only
D) describes the phenomenon of producing light by shining a beam of electrons by on any metal surface E) is not the same principle used in modern electric eyes and solar calculators
Answer: C
4)What is the energy in joules of a mole of photons with the energy of the 434 nm spectral line of hydrogen? ( h = 6.62 × 10-34 Js )
A) 9.21 × 10-4 J B) 2.76 × 10-4 J C) 2.76 × 105 J D) 434 J
E) 5.78 × 10-25 J Answer: C
5) What is the wavelength of a bullet that is 0.450 g traveling at 2000. m/s?
A) 1.49 × 10-40 m B) 2.94 × 10-24 m C) 7.36 × 10-34 m D) 2000. m
E) 7.36 × 10-37 m Answer: C
6) An atomic orbital represents:
A) the region of electron density for a covalent bond B) the shape of an atom
C) a fixed path that an electron follows around the nucleus of an atom D) the repulsion of all the electrons among themselves
E) the region of high probability for an electron around the nucleus of an atom Answer: E
7)The possible values of the magnetic quantum number, m , of a 3p electron are:
A) +1, -1 B) 0, 1, 2 C) 0
D) 2, 1, 0, -1, -2 E) -1, 0, +1 Answer: E
8) All of the terms below are quantum numbers EXCEPT:
A) magnetic B) spin C) valence
D) orbital angular momentum E) principal
Answer: C
9) Which of the following statements about orbital shapes is NOT true?
A) A 1s orbital is spherical.
B) Four of the 3d orbitals are alike except for the orientation with respect to the axes.
C) 2p orbitals have a node at r = 0.
D) There are 5 3d orbitals.
E) There are only two 2p orbitals, each directed along and x or y axis.
Answer: E
10) Which of the following subshells is correctly designated?
A) 3f2 B) 4d11 C) 2p6 D) 3s3 E) 1p5
Answer: C
11) Which of the following statements about electron spin is FALSE?
A) The electron's magnetic field can be oriented in two directions in the presence of an external magnetic field.
B)Electron spin only exists when m = 0.
C) An experiment with silver atoms passing through a magnetic field seems to prove that electron spin exists.
D) An electron produces a magnetic field.
E) Paired electrons produced no net magnetic field.
Answer: B
12) Arrange the following in order of increasing ENERGY:
UV radiation, visible radiation, X-rays, and microwaves.
A) visible < UV < X-rays < microwave B) microwave < visible < UV < X-rays C) X-ray < microwave < visible < UV D) X-rays < microwave < UV < visible
E) UV < X-rays < microwave < visible Answer: B
13) Use the spdf notation to write out the complete electron configuration of Br.
A) [Ar] 3d104p65s2 B) [Ar] 3d104s24p5 C) [Kr] 3d104s24p4 D) [Ar] 3d94s24p6
E) [Ar] 4s24p24d9 Answer: B
14) Why was Moseley so sure from his X-ray work that there were no other undiscovered elements besides the three that he predicted in the range of atomic numbers 13-79?
A) All of the possible atomic weights were assigned.
B) The rows on the periodic table were filled.
C) The columns of the periodic table were full.
D) Mendeleev didn't predict any more.
E) All of the integer atomic numbers were assigned.
Answer: E
15) The transition elements refer to what group of elements?
A) d-block elements B) s-block elements C) lanthanides D) actinides
E) p-block elements Answer: A
16) Which of the following pairs of elements are classified as metalloids?
A) argon and neon B) bromine and sulfur C) aluminum and silicon D) copper and silver
E) arsenic and germanium Answer: E
17) Most transition elements form some monatomic ions that are not:
A) isoelectronic with any neutral atom B) isoelectronic with any other species C) isoelectronic with any noble gas D) isoelectronic with any other cations
18) Which of the following statements is INCORRECT?
A) The ionization energy increases from left to right through a period of elements.
B) The atomic radius decreases from left to right through a period of elements.
C) The atomic radius increases down the periodic table.
D) Cations are larger than the atoms from which they are formed.
E) The metallic character of elements decreases from left to right through a period of elements.
Answer: D
19) Among the alkali metals, cesium reacts more rapidly than sodium because:
A) cesium has more neutrons B) cesium has more protons
C) cesium has a higher atomic weight
D) the valence electron of cesium is at a greater average distance from the nucleus E) cesium has more electrons
Answer: D
20) Which of the following isoelectronic species has the largest radius?
A) F- B) Mg2+ C) Ne D) Na+ E) O2-
Answer: E
21) Which of the following occurs for the representative elements going left to right across the period?
A) The outer electrons are held more weakly.
B) Electronegativity decreases.
C) Atomic size increases.
D) Forces of attraction between electron and nucleus increase because nuclear charge increases.
E) none of these Answer: D
22) The first ionization energy for rubidium is +403.0 kJ/mol. How much energy would be required to convert 17.1 g of gaseous rubidium to its gaseous +1 monatomic ion at constant temperature? (atomic mass of rubidium is 85.4078 g/mol)
A) 40.4 kJ B) 34.5 kJ C) 80.6 kJ D) 68.9 kJ E) 185 kJ
Answer: C
23) Choose the INCORRECT statement.
A) Ba2+ is smaller than Ba+.
B) The rare gas atoms complete the filling of the p orbitals.
C) The ionization energy of Ca+ is greater than that for Ca++.
D) When a metallic element unites with a nonmetallic element, electrons are lost by atoms of the metal and gained by atoms of the nonmetals.
E) Within a given sublevel, each orbital is usually occupied by a single electron before any orbital has two electrons.
Answer: C
24) Which of the following elements is likely to have the largest second ionization energy?
A) Mg B) Si C) Al D) Na
Answer: D
25) Which of the following reactions gives a positive value for the electron affinity?
A) S(g) + e- S-(g) B) Br(g) + e- Br-(g)
C) S-(g) + e- S2-(g) D) O(g) + e- O-(g)
Answer: C
26) Which of the following species is diamagnetic?
A) Al B) F- C) C D) S- E) Na
Answer: B
27) Choose a basic oxide.
A) MgO B)Cl2O C)SO2 D)CO2
Answer: A
28) Chlorine has a large negative electron affinity. Therefore, chlorine is most likely to:
A) have a small first ionization energy B) act as a reducing agent
C) release electrons readily to other atoms D) form a basic oxide
E) act as an oxidizing agent Answer: E
29) Which would you expect to have the highest melting point?
A) HCl B) HBr C) HI D)CF4
E) All have the same melting point.
Answer: C
30) List in order of increasing size: Cl-, Ar, K+, S2-, Ca2+.
A) K+ < S2- < Ar < Cl- < Ca2+
B) S2- < Cl- < Ar < K+ < Ca2+
C) Ca2+ < K+ < Ar < Cl- < S2- D) Ca2+ < S2- < K+ < Ar < Cl- E) Cl- < Ar < K+ < S2- < Ca2+
Answer: C
31)Complete 2 Na(s) + 2 H2O A)2 H2O(l) + 2 Na(s)
B)O2(g) + 2NaH2
C)2 NaH(s) + O2(g) + H2(g) D) 2 Na+ + 2 OH- + H2(g)
E) 2 NaH(s) + 2 OH- Answer: D
32) Choose the INCORRECT statement.
A) The core electrons are called valence electrons.
B) Covalent bonds are formed by atoms sharing electrons.
C) Ionic bonds are formed from atoms by a transfer of electrons.
D) Ionic bonds are formed by the attraction between cations and anions.
E) An octet is 8 outer-shell electrons.
Answer: A
33) In which of the following molecules would you expect the nitrogen-to-nitrogen bond to be the shortest?
A)N2 B)NH3 C)N2O D)N2O4 E)N2H4
Answer: A
34) Which chloride should have the greatest covalent character?
A) NaCl B) KCl C)CaCl2 D)BeCl2 E)BaCl2
Answer: D
35) Which of the following exhibits covalent bonding?
A)OF2 B) NaF C)K2S D) SrO E) LiH
Answer: A
36) Which of the following bonds is probably the most polar?
A)Se H in SeH2 B)C H in CH4 C)O H in H2O D)N H in NH3 E)P H in PH3 Answer: C
37) After drawing the Lewis dot structure of HC(O)OH, pick the INCORRECT statement from the following.
A) The oxygen not also bonded to hydrogen has a double bond to carbon.
B) The C-H bond is a single bond.
C) The O-H bond is a single bond.
D) The carbon has a lone pair.
E) Both oxygens have two lone pairs.
Answer: D
38) As indicated by Lewis structures, which of the following molecules would probably be unstable?
A)N2H6 B)SiH4 C)CH2F2 D)SF4 E)NH3
Answer: A
39) Which of the following species exhibits resonance?
A)PCl5 B)OF2 C)BrF3 D) ClO3 E)N2
Answer: D
40) Which of the following has a molecular structure best described as involving an "incomplete octet"?
A)BF3 B)NF3 C)OF2 D)F2 E)CF4
Answer: A
41)Choose the correct statement about the compound SO2.
A) The S atom has an unshared electron pair.
B) The O atoms have no unshared electron pairs.
C) The two S O bonds have different lengths since one is a single bond and the other a double bond.
D) The molecule has a linear structure.
E) The S O bonds are ionic in character.
Answer: A
42) Which of the following molecules is nonpolar?
A)CHCl3 B)H2O C)HClO4 D) HCN E)BCl3
Answer: E
43) Which of the following species has a pyramidal structure?
A)ClO2 B) ClO4 C) ClO3 D) ClO2
Answer: C
44)Given the bond enthalpies C C (348), C O (707), O O (498), H O (464), C H (414) all in kJ/mol, compute H° kJ/mol for the complete combustion of C7H16.
A) +2.57 × 103 kJ/mol B) -2.57 × 103 kJ/mol C) -2.93 × 103 kJ/mol D) -3.13 × 103 kJ/mol E) -2.43 × 103 kJ/mol Answer: D
45)After drawing the Lewis dot structure for CH2O, determine the number of single bonds, double bonds, and lone pairs on the central atom.
A) 3, 0, 1 B) 3, 1, 0 C) 2, 1, 0 D) 2, 1, 1 E) 1, 2, 0
Answer: C
46) What is the formal charge on N in NO3 ?
A) +2 B) 0 C) -1 D) -2 E) +1
Answer: E
47)The electron-pair geometry of H2O is ________.
A) tetrahedral B) linear C) bent D) V-shaped
E) trigonal planar Answer: A
48) Enthalpy is defined as:
A) the sum of the kinetic and potential energies B) the energy contained within a system C) the heat of combustion
49)What is the work done in joules by the system when H2 expands against a constant pressure of 75 atm at 45.3°C? The change in volume is 24.0 L.
A) -1.8 × 105 J B) 8.2 × 104 J C) 1.8 × 103 J D) -8.2 × 104 J E) 1.8 × 105 J Answer: A
50)The addition of 2.0 g He(g) to a vessel of 10.0 L fixed volume already containing O2(g) at 25°C and 740 mmHg will:
A) have no effect on the final gas pressure B) cause the final pressure to exceed 2 atm
C) bring the final pressure to just slightly more than 1 atm D) cause the final pressure to exceed 4 atm
E) produce a 20% increase in gas pressure Answer: B
