CHEM 1201 : CHEM 1201 FA10 Exam 3 WAnswers
CHEMISTRY 1201
Examination III (Chapters 7-8)
FALL 2010
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 features are consistent with a description of an atom of an alkaline earth metal?
A. it has two valence electrons
B. it has small first and second ionization energies
C. it loses two electrons and forms a cation with a +2 charge
D. it has a relatively large atomic radius compared to that of a halogen in the same period
E. all of the above
2. Which ions on the list below are isoelectronic with each other?
Na+ Mg2+ F- Cl- Rb+
A. only Na+ and Mg2+
B. Na+, Mg2+ and F-
C. only F- and Cl-
D. only Na+ and Rb+
E. none of the above
3. The size of an atom generally increases .
A. up a group and from right to left across a period.
B. up a group and from left to right across a period.
C. down a group and from left to right across a period.
D. down a group and from right to left across a period.
E. up a group and diagonally across the Periodic Table.
4. Which of the following elements has the lowest first ionization energy?
A. C B. Na C. Rb D. F E. He
5. The valence electron configuration for a 5th main group atom located in the 4th period is:
A. 5p4 B. 4s2 4p2 C. 4p5 D. 4s2 4p3 E. 4d5
6. Which alkali metal is expected to react with water in the most vigorous way?
A. Li B. Na C. K D. Rb E. Cs
7. Which of the following oxides is(are) acidic?
(i) CO2
(ii) N2O3
(iii) SO3
(iv) Na2O2
(v) CaO
A. (i) and (ii) only
B. (i), (ii) and (iii) only
C. (iv) and (v) only
D. (i), (iii) and (v) only
E. (ii), (iii), (iv) and (v)
8. In a N–O bond, which atom (and why) would adopt a negative partial charge, δ-?
Note: both the answer and the reason must be correct to receive credit for this question.
A. N; because N is more electronegative than O
B. N; because N is larger than O
C. O; because O is more electronegative than N
D. O; because O is smaller than N
E. neither; because this is a nonpolar covalent bond
9. What is the formal charge on the central N atom in a nitrite anion (NO2
-)? Which statement best
characterizes the nitrogen-oxygen bond in the actual anion (resonance hybrid)?
Formal charge on N nitrogen-oxygen bond characterization
A. −1 single
B. −1 intermediate between single and double
C. 0 single
D. 0 intermediate between single and double
E. +1 double
Document Summary
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. Rb: only na+ and mg2, na+, mg2+ and f and cl, only f, only na+ and rb, none of the above. N2o3 (i) (ii) (iii) so3 (iv) na2o2 (v) cao: (i) and (ii) only, (i), (ii) and (iii) only, (iv) and (v) only, (i), (iii) and (v) only, (ii), (iii), (iv) and (v) In a n o bond, which atom (and why) would adopt a negative partial charge, . +1 nitrogen-oxygen bond characterization single intermediate between single and double single intermediate between single and double double: consider the chlorate anion, clo3. Using the table of average bond energies below, what is the approximate hrxn for the reaction: The next five questions (21-25) are of true or false type.
