CHEM 1201 : CHEM 1201 FA11 Exam 3 WAnswers
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CHEMISTRY 1201
Examination III (Chapters 7-8)
FALL 2011
Form 1 Time allowed: 75 minutes
CALCULATORS ARE PERMITTED IN THIS EXAMINATION
Encode your answers on the SCANTRON sheet with soft pencil.
A Periodic Table is provided on the last page.
Turn in the SCANTRON to the exam proctor.
Encode 1 under Grade or Education on the scantron sheet
1) Which of the following orbital diagrams is an incorrect ground state electron configuration for an
ion?
A.
Fe3+:
[Ar]
↑
↑
↑
↑
↑
4s
3d
B.
V2+:
[Ar]
↑
↑
↑
3d
C.
N3–:
[He]
↑↓
↑↓
↑↓
↑↓
2s
2p
D.
Zn2+:
[Ar]
↑↓
↑↓
↑↓
↑↓
↑↓
3d
E.
Ca2+:
[Ne]
↑↓
↑↓
↑↓
↑↓
3s
3p
2) Which ions are isoelectronic with the potassium cation, K+?
Na+ P3– Ca2+ Al3+
A. Na+ only
B. Ca2+ only
C. P3– only
D. Na+ and Al3+ only
E. P3– and Ca2+ only
3) Of the ions below, only does not have the octet of valence electrons.
A. S2– B. Mg2+ C. I– D. In+ E. N3–
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4) Which of the following anions has the smallest radius?
A. Cl– B. Br– C. I– D. F– E. At–
5) Consider the following electron configurations of N and O to explain why the first ionization energy
of oxygen is lower than that of nitrogen ( I1(O) < I1(N) ).
N:
[He]
↑↓
↑
↑
↑
2s
2p
O:
[He]
↑↓
↑↓
↑
↑
2s
2p
A. The nucleus of oxygen has more protons to attract its p electrons.
B. Oxygen has fewer core electrons than nitrogen.
C. Paired electrons in the p4 configuration of oxygen repel each other.
D. Electrons in the 2p subshell in oxygen violate Pauli’s exclusion principle.
E. Electrons in the 2p subshell in nitrogen violate Hund’s rule.
6) Which atom would have the fourth ionization energy hugely greater than the third ionization energy?
A. Be B. Al C. C D. Li E. N
7) Which of the following correctly ranks elements in order of increasing atomic radius (smallest radius
first).
A. S < P < As
B. Na < Mg < Al
C. I < Br < Cl
D. S < Ga < F
E. Ar < Si < P
8) Which of the following equations correctly corresponds to the electron affinity of chlorine?
A. Cl(g) + e– ! Cl+(g)
B. Cl(g) ! Cl+(g) + e–
C. Cl(g) + e– ! Cl–(g)
D. Cl–(g) ! Cl(g) + e–
E. Cl+(g) ! Cl2+(g) + e–
9) Which of the following oxides is expected to form an acidic solution if dissolved in water?
A. KO2 B. CaO C. Na2O D. CO2 E. MgO
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10) Which of the following equations correctly describes the reaction between a basic oxide and a dilute
solution of a strong acid?
A. CO2(g) + 4 HCl(aq) ! CCl4(l) + 2 H2O(l)
B. CO2(g) + 2 NaOH(aq) ! Na2CO3(aq) + H2O(l)
C. K2O(s) + 2 NaOH(aq) ! Na2O(s) + 2 KOH(aq)
D. K2O(s) + 2 HCl(aq) ! 2 KCl(aq) + H2O(l)
E. CaO(s) + H2O(l) ! Ca(OH)2(aq)
11) Consider the general valence electron configuration of ns2 np5 and the following statements:
(i) all elements with this electron configuration are solid at room temperature and 1 atm
pressure.
(ii) elements with this electron configuration are transition metals.
(iii) elements with this electron configuration form -1 ions.
(iv) elements with this electron configuration have large negative electron affinities.
Which statement(s) is(are) true?
A. (i) and (ii) only
B. (iii) and (iv) only
C. (ii) and (iii) only
D. (i), (iii) and (iv)
E. (iv) only
12) Which of the following orders of electronegativity is incorrect?
A. Se < S < O
B. C < N < O
C. Si < P < N
D. I < Br < Cl
E. S < P < Si
13) Which order is correct for increasing polarity (least polar first)?
Si-Cl P-Cl Si-Si
least polar ……most polar
A. Si-Si < P-Cl < Si-Cl
B. Si-Si < Si-Cl < P-Cl
C. P-Cl < Si-Cl < Si-Si
D. Si-Cl < P-Cl < Si-Si
E. P-Cl < Si-Si < Si-Cl
