1071-2nd Chem Exam-1071128(A)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The halogens, alkali metals, and alkaline earth metals have __________ valence electrons, respectively.
A) 7, 4, and 6 B) 2, 7, and 4 C) 8, 2, and 3 D) 7, 1, and 2 E) 1, 5, and 7 Answer: D
2) The only noble gas without eight valence electrons is __________.
A) He B) Ar C) Kr D) Ne
E) All noble gases have eight valence electrons.
Answer: A
3) For a given arrangement of ions, the lattice energy increases as ionic radius __________ and as ionic charge __________.
A) decreases, decreases B) increases, increases C) decreases, increases D) increases, decreases
E) This cannot be predicted.
Answer: C
4) What is the maximum number of double bonds that a hydrogen atom can form?
A) 0 B) 1 C) 2 D) 3 E) 4
Answer: A
5) Given the electronegativities below, which covalent single bond is most polar?
Element: H C N O
Electronegativity: 2.1 2.5 3.0 3.5
A) O N B) C H C) N H D) O C E) O H
Answer: E
6) The ion PO43- has __________ valence electrons.
A) 24 B) 32 C) 27 D) 14 E) 29
Answer: B
7) The formal charge on sulfur in SO42- is __________, where the Lewis structure of the ion is:
8) How many equivalent resonance forms can be drawn for SO2 without expanding octet on the sulfur atom (sulfur is the central atom)?
A) 2 B) 1 C) 4 D) 3 E) 0
Answer: A
9) Using the table of average bond energies below, the H for the reaction is __________ kJ.
H-C C-H (g) + H-I (g) H2C CHI (g)
Bond: C C C=C H-I C-I C-H
D (kJ/mol): 839 614 299 240 413
A) +129 B) -931 C) -506 D) -129 E) +506
Answer: D
10) Which of the following has eight valence electrons?
A) Cl- B) Ti4+
C) Na+
D) Kr
E) all of the above Answer: E
11) An electron in a(n) __________ subshell experiences the greatest effective nuclear charge in a many-electron atom.
A) 3d B) 3p C) 3f D) 3s E) 4s
Answer: D
12) A tin atom has 50 electrons. Electrons in the __________ subshell experience the lowest effective nuclear charge.
A) 1s B) 3p C) 5s D) 3d E) 5p
Answer: E
13) Oxides of the active metals combine with water to form __________.
A) hydrogen gas B) oxygen gas C) metal hydroxides D) water and a salt
E) metal hydrides Answer: C
14) The substance __________ is always produced when an active metal reacts with water.
A) NaOH B) H2O C) H2 D) CO2 E) O2
Answer: C
15) The most common and stable allotrope of sulfur is __________.
A) S2 C) S4B) S D) S8
E) Sulfur does not form allotropes.
Answer: D
16) The element phosphorus exists in two forms in nature called white phosphorus and red phosphorus. These two forms are examples of __________.
A) noble gases B) isotopes C) oxidation D) metalloids E) allotropes Answer: E
17) Of the halogens, which are gases at room temperature and atmospheric pressure?
A) fluorine, chlorine, and bromine B) fluorine, bromine, and iodine C) fluorine and chlorine
D) fluorine, chlorine, bromine, and iodine E) fluorine, chlorine, and iodine
Answer: C
18) 2 F2 (g) + 2 H2O (l) __________
A) 2 F- (aq) + 2 H+ (aq) + H2O2 (aq) B) 2 HF2 (aq) + 2 OH- (aq)
C) 4 HF (aq) + O2 (g) D) 2 HF (aq) + 2 HFO (aq)
E) 4 HF (aq) + 2 O2- (aq) Answer: C
19) In which set of elements would all members be expected to have very similar chemical properties?
A) S, Se, Si B) Na, Mg, K C) O, S, Se D) N, O, F E) Ne, Na, Mg
Answer: C
20) Screening of the nuclear charge by core electrons in atoms is __________.
A) less efficient than that by valence electrons
B) responsible for a general decrease in atomic radius going down a group C) more efficient than that by valence electrons
D) essentially identical to that by valence electrons
E) both essentially identical to that by valence electrons and responsible for a general decrease in atomic radius going down a group
Answer: C
21) What is the wavelength of light (nm) that has a frequency 4.62 × 1014 s-1?
A) 1.39 × 1023 B) 1.07 × 106 C) 649 D) 932 E) 1.54 × 10-3
22) The uncertainty principle states that __________.
A) it is impossible to know how many electrons there are in an atom B) matter and energy are really the same thing
C) it is impossible to know the exact position and momentum of an electron D) there can only be one uncertain digit in a reported number
E) it is impossible to know anything with certainty Answer: C
23) The de Broglie wavelength of a car (1.0 × 103 kg) traveling at 75 km/hr is __________ m.
A) 1.4 × 1035 B) 8.8 × 10-39 C) 3.2 × 10-38 D) 1.4 × 10-35 E) 3.2 × 10-35 Answer: C
24) Of the following transitions in the Bohr hydrogen atom, the __________ transition results in the emission of the lowest-energy photon.
A) n = 3 n = 6 B) n = 1 n = 4 C) n = 6 n = 3 D) n = 6 n = 1 E) n = 1 n = 6 Answer: C
25) The angular momentum quantum number is 3 in __________ orbitals.
A) a B) s C) d D) f E) p
Answer: D
26) Which of the following is a valid set of four quantum numbers? (n, l, ml, ms)
A) 2, 2, 1, -1/2 B) 1, 1, 0, -1/2 C) 2, 1, 0, +1/2 D) 1, 0, 1, +1/2 E) 2, 1, +2, +1/2 Answer: C
27) The ground state electron configuration of Fe is __________.
A) 1s22s23s23p63d6 B) 1s22s23s23p10
C) 1s22s22p63s23p64s24d6 D) 1s22s22p63s23p64s2
E) 1s22s22p63s23p64s23d6 Answer: E
28) The ground-state electron configuration of __________ is [Ar]4s13d5.
A) Cr B) V C) K D) Fe E) Mn
Answer: A
29) The electron configuration of a ground-state Ag atom is __________.
A) [Ar]4s14d10 B) [Kr]5s24d10 C) [Ar]4s24d9 D) [Kr]5s14d10 E) [Kr]5s23d9 Answer: D
30) Which electron configuration represents a violation of Hund's rule for an atom in its ground state?
A)
B)
C)
D)
E)
Answer: C
31) Which one of the following statements is true?
A) Enthalpy is a state function.
B) Enthalpy is an intensive property.
C) H is the value of q measured under conditions of constant volume.
D) The enthalpy change of a reaction is the reciprocal of the H of the reverse reaction.
E) The enthalpy change for a reaction is independent of the state of the reactants and products.
Answer: A
32) The change in the internal energy of a system that releases 2,500 J of heat and that does 7,655 J of work on the surroundings is __________ J.
A) -10,155 B) 5,155 C) -1.91 × 107 D) 10,155 E) -5,155
Answer: A
33) A 22.44 g sample of iron absorbs 180.8 J of heat, upon which the temperature of the sample increases from 21.1
°C to 39.0 °C. What is the specific heat of iron?
A) 0.840 B) 0.450 C) 0.820 D) 0.140 E) 0.900
Answer: B
34) The temperature of a 12.58 g sample of calcium carbonate [CaCO3 (s)] increases from 23.6 °C to 38.2 °C. If the
35) The value of H° for the reaction below is -126 kJ. __________ kJare released when 2.00 mol of NaOH is formed in the reaction?
2Na2O2 (s) + 2H2O (l) 4NaOH (s) + O2 (g)
A) -126 B) 3.9 C) 252 D) 63 E) 7.8
Answer: D
36) Given the following reactions
Fe2O3 (s) + 3CO (s) 2Fe (s) + 3CO2 (g) H = -28.0 kJ 3Fe (s) + 4CO2 (s) 4CO (g) + Fe3O4 (s) H = +12.5 kJ the enthalpy of the reaction of Fe2O3 with CO
3Fe2O3 (s) + CO (g) CO2 (g) + 2Fe3O4 (s) is __________ kJ.
A) -59.0 B) 40.5 C) +109 D) -15.5 E) -109
Answer: A
37) Given the following reactions
H2O (l) H2O (g) H = 44.01 kJ
2H2 (g) + O2 (g) 2H2O (g) H = -483.64 kJ
the enthalpy for the decomposition of liquid water into gaseous hydrogen and oxygen 2H2O (l) 2H2 (g) + O2 (g)
is __________ kJ.
A) -395.62 B) 527.65 C) -527.65 D) 439.63 E) 571.66
Answer: E
38) For which one of the following equations is H°rxn equal to Hf° for the product?
A) 2CO (g) + O2 (g) 2CO2 (g) B) N2 (g) + O3 (g) N2O3 (g)
C) CH4 (g) + 2Cl2 (g) CH2Cl2 (l) + 2HCl (g) D) Xe (g) + 2F2 (g) XeF4 (g)
E) C (diamond) + O2 (g) CO2 (g) Answer: D
39) Given the data in the table below, H°rxn for the reaction 4NH3 (g) + 5O2 (g) 4NO (g) + 6H2O (l) is __________ kJ.
Substance Hf° (kJ/mol)
H2O (l) -286
NO (g) 90
NO2 (g) 34
HNO3 (aq) -207
NH3 (g) -46
A) -150 B) -1172 C) -1540 D) -1892
E) The Hf° of O2 (g) is needed for the calculation.
Answer: B
40) Given the data in the table below, H°rxn for the reaction PCl3 (g) + 3 HCl (g) 3 Cl2 (g) + PH3 (g) is __________ kJ.
Compound Hf° (kJ/mol) PCl3 (g) -288.07 HCl (g) -92.30
PH3 (g) 5.40
A) -570.37 B) -385.77 C) 570.37 D) 385.77
E) The H°f of Cl2 (g) is needed for the calculation.
Answer: C
