KEY Exam2 1311 F16 v C - exam 2 version D, test-taking policy and form at are similar for every year PDF

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exam 2 version D, test-taking policy and form at are similar for every year...

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CHEM 1311: General Chemistry 1, Fall 2016 Exam #2, October 15, 2016 Class section: Instructor Taylor Sibert Dieckmann Dieckmann Taylor Wijenayake

Section # 001 002 003 004 005 501

Class time 9:00 to 9:50 am 10:00 to 10:50 am 11:00 to 11:50 am 1:00 to 1:50 pm 2:00 to 2:50 pm 5:30 to 6:45 pm

EXAM TYPE: C You have 80 minutes to answer 34 questions AND bubble the scantron. No additional time to bubble will be given. _________________________________________________________________________________ Scantron Use In general: 1. For this exam, you are allowed to use ONLY a TI-30X IIS, TI-30X IIB or TI-30Xa that you have at your desk. You MAY NOT borrow another person’s calculator. You MAY NOT use your cell phone, PDA, or other non-calculator device as a calculator. 2. Your cell phone should be turned OFF and stored in your bag or on the floor, under your seat. NO wristwatches will be permitted to be worn during this exam. 3. Use ONLY a #2 pencil to fill out the scantron sheet. Do not use a pen or marker. 4. When filling in the bubbles on the scantron, be sure to fill in bubble completely, and only one bubble for each entry. Pay attention to line numbers on the scantron so that you put the answer in the correct spot. 5. When you first get the exam, check to make sure you have all pages of the exam and one periodic table. You should also have one scantron sheet. If you don’t have any of these, contact us immediately. 6. We will announce periodically how much time has elapsed/is remaining. 7. If you have a question, ASK (if taking the exam at the Office of Student AccessAbility or the Testing Center, let your proctor know and they can call immediately to get an answer to your question) FILLING IN SCANTRON PERSONAL INFO: Bubble info: 1. I.D. NUMBER:

4-digit exam number (left justified)

2. NAME:

LAST NAME

3. TEST FORM:

exam type (A, B, C or D)

4. SUBJECT SCORE:

your section number (see above for list)

Vertical lines: 1. NAME:

“Exam 2” GOOD LUCK!

space

FIRST NAME

space

MI (left justified)

CHEM 1311: Exam #2

October 15, 2016

Page 2 of 6

1. Which of the following molecules has a net dipole moment (i.e. is polar)? A. KrF2 B. CCl4 C. CO2 D. BeCl2 E. SF2 __________________________________________________________________________________ 2. How many equivalent resonance structures are possible for the perbromate ion (BrO4– )? A. 1 B. 2 C. 3 D. 4 E. 5 __________________________________________________________________________________ 3. Which of the following is the correct name for FePO3? A. iron(III) phosphate, ferric phosphate B. iron(II) phosphate, ferrous phosphate C. iron(III) phosphite, ferric phosphite D. iron(II) phosphite, ferrous phosphite E. iron phosphorus trioxide __________________________________________________________________________________ 4. Which of the following elements has the largest first ionization energy? A. Rb B. Mg C. Na D. Cl E. Br __________________________________________________________________________________ 5. A 4.7 gram sample contains 1.82 g calcium, 0.94 g phosphorus and the rest is oxygen. What is the empirical formula for this compound? A. Ca1.5PO4 B. CaPO C. Ca2PO2 D. Ca3PO3 E. Ca3P2O8 __________________________________________________________________________________ 6. What is the formal charge on the carbon atom in carbon monoxide? A. 0 B. 1 C. 2 D. 4 E. –1 __________________________________________________________________________________ 7. Which of the following sets of names and compounds is correct? A. HClO (aq), hypochlorous acid B. H3PO4 (aq), phosphorous acid C. HCl (aq), hypochloric acid D. H2CrO4 (aq), perchromic acid E. H2SO3 (aq), sulfuric acid __________________________________________________________________________________ 8. What is the correct electron configuration of a magnesium ion, Mg2+ ? B. [Ne] C. [Ar] D. [Ar] 3s1 E. [Ne] 3s2 A. [Ne] 3s1 __________________________________________________________________________________ 9. Which of the following Lewis structures is the BEST description of the bonding in ozone, O3? a.

d.

O

O

O

b. 2-

O

O

O

e.

O

O

O

O

O

O

c.

O

O

O

__________________________________________________________________________________ 10. Which is the MOST polar bond? A. S–H B. Si–H C. Cl–H D. O–H E. H–H __________________________________________________________________________________

CHEM 1311: Exam #2

October 15, 2016

Page 3 of 6

11. What types of intermolecular forces exist between hydrogen iodide molecules? I. London forces II. dipole-dipole interactions III. hydrogen bonding IV. ion-dipole interactions A. I and II only B. I only C. III only D. II and III only E. I, II, and III only __________________________________________________________________________________ 12. How many individual ions are in 18.2 grams of Al2S3? A. 7.30 × 1023 ions B. 1.85 × 1023 ions C. 9.28 × 1023 ions 23 23 D. 3.65 × 10 ions E. 5.12 × 10 ions __________________________________________________________________________________ 13. The radii of the species, Y,Y+, and Y– increase in the following order: A. Y+ < Y < Y– B. Y+ < Y– < Y C. Y < Y– < Y+ D. Y < Y+ < Y– E. Y– < Y < Y+ __________________________________________________________________________________ 14. Predict the ideal bond angle(s) in the chlorite ion: A. 90° B. 109.5° C. 120° D. 180° E. more than one of the other answers is correct __________________________________________________________________________________ 15. Which of these ionic solids would have the largest magnitude lattice energy? A. KF B. CaBr2 C. NaF D. MgO E. CaI2 __________________________________________________________________________________ 16. Select the best Lewis structure for ClCN. A. C. E.

Cl Cl

Cl

C C

N

D.

N

C

B.

Cl

Cl

C

C

N

N

N

__________________________________________________________________________________ 17. What is the Te–O bond order in the “best” Lewis structure of the tellurite ion (TeO32–)? A. 1 B. 1.75 C. 1.33 D. 1.5 E. 1 and 2 __________________________________________________________________________________ 18. β-Carotene, an organic strongly colored red-orange pigment abundant in plants and fruits, has a molecular formula of C40H56. What is its empirical formula? A. C0.71H B. CH1.4 C. C10H14 D. C5H7 E. C40H56 __________________________________________________________________________________ 19. How many resonance structures are possible for carbonate, CO32– ? A. 1 B. 2 C. 3 D. 4 E. 0 __________________________________________________________________________________

CHEM 1311: Exam #2

October 15, 2016

Page 4 of 6

20. Which of the following sets of names and compounds is incorrect? A. KN3 potassium azide B. LiCl lithium chloride C. NO nitrogen oxide D. AlH3 aluminum hydride E. CO carbon monoxide __________________________________________________________________________________ 21.Which one of the following equations correctly represents the process involved in the second electron affinity of As? A. As(g) + e– → As–(g) B. As–(g) + e– → As2–(g) + – C. As(g) → As (g) + e D. As–(g) → As(g) + e– 2– – 3– E. As (g) + e → As (g) __________________________________________________________________________________ 22. How many lone pairs of electrons are on the iodine atom in the Lewis structure of IF3? A. 0 B. 1 C. 2 D. 3 E. 4 __________________________________________________________________________________ 23. Arrange the following in order of increasing boiling point: CsF, CH3Br, CH3OH, CH4 A. CH4 < CH3Br < CH3OH < CsF B. CH3OH < CH4 < CH3Br < CsF C. CsF < CH3Br < CH3OH < CH4 D. CH4 < CH3OH < CH3Br < CsF E. CH3OH < CH3Br < CsF < CH4 __________________________________________________________________________________ 24. Select the correct Lewis structure for nitrogen trifluoride. A. F

N

F

B .

F

N

F

F

F

C.

D. F

N

F

F

F

N

F

F

E. F

N

F

F

__________________________________________________________________________________ 25. What is the molecular geometry for BrF5? A. Square pyramidal B. Trigonal pyramidal C. T-shaped D. Trigonal planar E. See saw __________________________________________________________________________________

CHEM 1311: Exam #2

October 15, 2016

Page 5 of 6

26. What is the molar mass of MgCl2? A. 127.21 g mol–1 B. 75.76 g mol–1 C. 59.76 g mol–1 D. 84.07 g mol–1 E. 95.21 g mol–1 __________________________________________________________________________________ 27. Select the element whose Lewis symbol is correct: A. Sn

B.

Si

C. He

D. Cl

E.

Ge

__________________________________________________________________________________ 28. Which of the following is false concerning electronegativity? A. Fluorine is the most electronegative atom B. Electronegativity can be measured by observing individual atoms in the gas phase C. Electronegativity affects covalent bonds D. All electronegativity scales are relative E. Larger atoms generally have lower electronegativities than smaller atoms __________________________________________________________________________________ 29. The best Lewis structure for sulfuric acid has zero formal charges, sulfur as the central atom, and no bonds between S and H. How many total single and double bonds, respectively, are there in this Lewis structure? A. 2 single, 4 double B. 6 single, no double C. 4 single, 2 double D. 5 single, 1 double E. 4 have 1 ½ bonds, no single, no double __________________________________________________________________________________ 30. What is the electron domain geometry around the krypton in KrCl4 ? A. linear B. trigonal planar C. tetrahedral D. trigonal bipyramidal E. octahedral __________________________________________________________________________________ 31. In neutral molecules, how many bonds are commonly formed by nitrogen? A. 5 B. 4 C. 3 D. 2 E. 1 __________________________________________________________________________________ 32. Predict the actual bond angle(s) in nitrite (best estimate): A. 180° exactly B. < 90° C. < 109.5° D. < 120° E. < 180° __________________________________________________________________________________ 33. What is the percent composition of chlorine in cobalt(II) chloride hexahydrate? A. 29.8% B. 24.8% C. 47.9% D. 39.8% E. 54.6% __________________________________________________________________________________ 34. What is the electron configuration of Zn2+? A. [Ar] 4s2 3d10

B. [Ar]3d10

C. [Ar] 4s2 3d8

D. [Ar] 4s2 3d10 4p1

E. [Ar] 4s1 3d10 __________________________________________________________________________________ END OF QUESTIONS

CHEM 1311: Exam #2

October 15, 2016

Page 6 of 6

Potentially Useful Information Avogadro’s Number:

NA = 6.022 x 1023

Constant for Bohr model of H atom:

b = 2.180 x 10–18 J

Speed of light:

c = 2.998 x 108 m s–1

Planck’s constant:

h = 6.626 x 10–34 J s

1 J = 1 kg m2 s–2 electron: proton: neutron:

mass (me) = 9.1093897 x 10–28 g mass = 1.673 x 10–24 g mass = 1.675 x 10–24 g

1 in = 2.54 cm (exactly) 1 amu = 1.66054 x 10–24 g

1 ft = 12 in

charge (e) = –1.60 x 10–19 C

1 mi = 5280 ft...