1061-2nd Chem Exam-1061206(A)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) An FM radio station broadcasts electromagnetic radiation at a frequency of 100.6 MHz. The wavelength of this radiation is __________ m.
A) 3.018 × 1010 B) 2.982 × 106 C) 2.982 D) 3.018 × 1016 E) 0.3353 Answer: C
2) It takes 261 kJ/mol to eject electrons from a certain metal surface. What is the longest wavelength of light (nm) that can be used to eject electrons from the surface of this metal via the photoelectric effect?
A) 165 B) 552 C) 233 D) 458 E) 725
Answer: D
3) Of the following transitions in the Bohr hydrogen atom, the __________ transition results in the emission of the highest-energy photon.
A) n = 1 n = 6 B) n = 3 n = 6 C) n = 6 n = 3 D) n = 6 n = 1 E) n = 1 n = 4 Answer: D
4) What is the de Broglie wavelength (m) of a 25-g object moving at a speed of 5.0 m/s?
A) 3.32 × 10-36 B) 6.6 × 10-36 C) 1.9 × 1032 D) 5.3 × 10-33 E) 3.02 × 1045 Answer: D
5)Which set of three quantum numbers (n, l, ml) corresponds to a 3p orbital?
A) 3,0,1 B) 3,1,0 C) 3,3,1 D) 3,0,0 E) 3,2,0
Answer: B
6)Which one of the following represents an acceptable possible set of quantum numbers (in the order n, l, ml, ms) for an electron in an atom?
A) 2, 1, 0, 0 B) 2, 0, 2, +1/2 C) 2, 2, 0, 1/2 D) 2, 0, 1, -1/2 E) 2, 1, -1, 1/2 Answer: E
7) Which electron configuration denotes an atom in its ground state?
A)
B)
C)
D)
E)
Answer: E
8) The element that has a valence configuration of 4s1 is __________.
A) Rb B) Na C) Cs D) K E) Li
Answer: D
9) The complete electron configuration of gallium, element 31, is __________.
A) 1s22s22p103s23p104s23d3 B) 1s42s42p103s43p9
C) 1s42s42p83s43p84s3 D) 1s42s42p63s43p64s43d3
E) 1s22s22p63s23p63d104s24p1 Answer: E
10) The ground-state electron configuration of the element __________ is [Kr]5s14d5.
A) Mo B) Nb C) Tc D) Mn E) Cr
Answer: A
11) In which set of elements would all members be expected to have very similar chemical properties?
A) Ne, Na, Mg B) S, Se, Si C) Na, Mg, K D) O, S, Se E) N, O, F
Answer: D
12) Screening of the nuclear charge by core electrons in atoms is ________.
A) responsible for a general decrease in atomic radius going down a group B) less efficient than that by valence electrons
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
Consider the following electron configurations to answer the questions that follow:
(i) 1s2 2s2 2p6 3s1 (ii) 1s2 2s2 2p6 3s2 (iii) 1s2 2s2 2p6 3s2 3p1 (iv) 1s2 2s2 2p6 3s2 3p4 (v) 1s2 2s2 2p6 3s2 3p5
13) The electron configuration belonging to the atom with the highest second ionization energy is ________.
A) (i) B) (ii) C) (iii) D) (iv) E) (v)
Answer: A
14) The electron configuration of the atom with the most negative electron affinity is ________.
A) (i) B) (ii) C) (iii) D) (iv) E) (v)
Answer: E
15) Which equation correctly represents the electron affinity of calcium?
A) Ca (g) Ca- (g) + e- B) Ca (g) + e- Ca- (g) C) Ca+ (g) + e- Ca (g) D) Ca (g) Ca+ (g) + e- E) Ca- (g) Ca (g) + e- Answer: B
16) The list that correctly indicates the order of metallic character is ________.
A) F > Cl > Br B) Li > Na > K C) O > Se > S D) Sr > Ca > Mg
E) C > Ge > Si Answer: D
17) Of the hydrogen halides, only ________ is a weak acid.
A) HBr (aq) B) HF (aq) C) HI (aq) D) HCl (aq)
E) They are all weak acids.
Answer: B
18) The reaction of alkali metals with oxygen produce ________.
A) oxides B) superoxides C) peroxides D) all of the above
E) none of the above Answer: D
19) Hydrogen is unique among the elements because ________.
1. It has only one valence electron.
2. It is the only element that can emit an atomic spectrum.
3. Its electron is not at all shielded from its nucleus.
4. It is the lightest element.
5. It is the only element to exist at room temperature as a diatomic gas.
A) 1, 2, 3, 4, 5 B) 2, 3, 4 C) 3, 4 D) 1, 3, 4 E) 1, 2, 3, 4
Answer: C
20)Na reacts with element X to form an ionic compound with the formula Na3X. Ca will react with X to form ________.
A)Ca3X B)Ca2X3 C)CaX2 D)Ca3X2 E) CaX
Answer: D
21) Which of the following statements is false?
A) The enthalpy change for a reaction is equal in magnitude, but opposite in sign, to the enthalpy change for the reverse reaction.
B) Internal energy is a state function.
C) Enthalpy is an intensive property.
D) The enthalpy change for a reaction is equal to the heat change of the reaction under conditions of constant pressure.
E) The enthalpy change for a reaction depends on the state of the reactants and products.
Answer: C
22) The change in the internal energy of a system that absorbs 2,500 J of heat and that does 7,655 J of work on the surroundings is __________ J.
A) 10,155 B) -10,155 C) 5,155 D) -5,155 E) 1.91 × 107
Answer: D
23) Which of the following is a statement of the first law of thermodynamics?
A) Energy lost by the system must be gained by the surroundings.
B) Ek = 1 2m 2
C) A negative H corresponds to an exothermic process.
D) E = Efinal - Einitial E) 1 cal = 4.184 J (exactly) Answer: A
24) What is the enthalpy change (in kJ) of a chemical reaction that raises the temperature of 250.0 mL of solution having a density of 1.25 g/mL by 7.80 °C? (The specific heat of the solution is 3.74 joules/gram-K.)
A) -12.51 B) 6.51 C) -9.12 D) -7.43 E) 8.20
Answer: C
25)An 8.29 g sample of calcium carbonate [CaCO3 (s)] absorbs 50.3 J of heat, upon which the temperature of the sample increases from 21.1 °C to 28.5 °C. What is the specific heat of calcium carbonate?
A) 1.1 B) 4.2 C) 2.2 D) .63 E) .82
Answer: E
26) The value of H° for the reaction below is -790 kJ. The enthalpy change accompanying the reaction of 0.95 g of S is __________ kJ.
2S (s) + 3O2 (g) 2SO3 (g)
A) -12 B) 12 C) -23 D) 23 E) -790
Answer: A
27) H for the reaction
IF5 (g) IF3 (g) + F2 (g) is __________ kJ, give the data below.
IF (g) + F2 (g) IF3 (g) H = -390 kJ IF (g) + 2 F2 (g) IF5 (g) H = -745 kJ
A) +35 B) +355 C) -35 D) -1135 E) +1135
Answer: B
28)For which one of the following reactions is the value of H°rxn equal to H°f for the product?
A)2 H2 (g) + O2 (g) 2 H2O (l) B)2 H2 (g) + O2 (g) 2 H2O (g) C)N2 (g) + O2 (g) 2 NO (g)
D)2 C (s, graphite) + 2 H2 (g) C2H4 (g) E)H2O (l) + 1/2 O2 (g) H2O2 (l) Answer: D
29) Given the data in the table below, H°rxn for the reaction Ca(OH)2 + 2H3AsO4 Ca(H2AsO4)2 + 2H2O is __________ kJ.
Substance Hf° (kJ/mol)
Ca(OH)2 -986.6
H3AsO4 -900.4
Ca(H2AsO4)2 -2346.0
H2O -285.9
A) -4519 B) -76.4 C) -130.4 D) -4219 E) -744.9
Answer: C
30) Given the data in the table below and H°rxn for the reaction
SO2Cl2 (g) + 2H2O (l) H2SO4 (l) + 2HCl (g) H° = -62 kJ H°f of HCl (g) is __________ kJ/mol.
Substance Hf° (kJ/mol)
SO2 (g) -297
SO3 (g) -396
SO2Cl2 (g) -364 H2SO4 (l) -814
H2O (l) -286
A) 60 B) -92 C) -184 D) 30
E) Insufficient data are given.
Answer: B
31) In which of the molecules below is the carbon-carbon distance the shortest?
A) H-C C-H B)H2C C CH2 C)H3C-CH3 D)H3C-CH2-CH3
E)H2C CH2 Answer: A
32) Which of the following has the bonds correctly arranged in order of increasing polarity?
A) N F, Be F, Mg F, O F B) Be F, Mg F, N F, O F C) Mg F, Be F, N F, O F D) O F, N F, Be F, Mg F E) O F, Be F, Mg F, N F Answer: D
33)The Lewis structure of N2H2 shows ________.
A) each nitrogen has one nonbonding electron pair B) a nitrogen-nitrogen single bond
C) a nitrogen-nitrogen triple bond
D) each nitrogen has two nonbonding electron pairs E) each hydrogen has one nonbonding electron pair Answer: A
For the questions that follow, consider the BEST Lewis structures of the following oxyanions:
(i) NO2- (ii) NO3- (iii) SO32- (iv) SO42- (v) BrO3- 34) There can be four equivalent best resonance structures of ________.
A) (i) B) (ii) C) (iii) D) (iv) E) (v)
Answer: D
35) A valid Lewis structure of ________ cannot be drawn without violating the octet rule.
A)NI3 B)ICl5 C)SO2 D)SiF4 E)CO2
Answer: B
36)The Lewis structure of PF3 shows that the central phosphorus atom has ________ nonbonding and ________
bonding electron pair(s).
A) 1, 2 B) 3, 1 C) 3, 3 D) 2, 2 E) 1, 3
Answer: E
37) In the Lewis structure of HCO3-, the formal charge on H is ________, and the formal charge on C is ________.
A) 0, -1 B) +1, -1 C) 0, 0 D) -1, +1 E) -1, -1
Answer: C
38) How many equivalent resonance forms can be drawn for CO32-? (Carbon is the central atom.)
A) 2 B) 4 C) 0 D) 1 E) 3
Answer: E
39) Of the following, ________ cannot accommodate more than an octet of electrons.
A) Ni B) Os C) Sb D) Sc E) Be
Answer: E
40) Using the table of average bond energies below, the H for the reaction is ________ kJ.
Bond: C C C-C H-I C-I C-H
D (kJ/mol): 839 348 299 240 413
A) +160 B) -160 C) +63 D) -217 E) -63
Answer: D
