CHEM 1411 Exam 3

9) Of the following elements, which has the lowest electronegativity? A) Tl B) As C) S D) Sn

A

40) Which ionic compound would be expected to have the highest lattice energy? A) RbO2 B) Li2O C) KO2 D) Na2O2

B

49) Which element, indicated by letter on the periodic table, is able to form compounds that do not obey the octet rule? A) A B) B C) C D) D

B

25) In the most acceptable electron-dot structure for carbonyl fluoride, COF2 the central atom is A) O, which is singly-bonded to C B) C, which is singly-bonded to O. C) C, which is doubly-bonded to O. D) O, which is doubly-bonded to C.

C

29) Which element, indicated by letter on the periodic table above, has a 2+ ion with the electron configuration [Ar]3d 10? A) A B) B C) C D) D

C

33) Consider a molecule with the following connections: When a valid electron dot structure is written, how many double bonds will the molecule contain? A) 4 B) 1 C) 2 D) 0

C

34) Which sphere represents the monatomic cation? A) A B) B C) C D) D

C

37) Which sphere most likely represents the F- ion? A) A B) B C) C D) D

C

39) Atoms of which element, indicated by letter on the periodic table above, would be expected to have the highest first ionization energy, E i1? A) A B) B C) C D) D

C

4) Which bond should have the highest bond dissociation energy? A) N-H B) N=N C) N(triple bond)N D) N-N

C

40) Which molecule has the weakest bonds? A) CF4 B) CBr4 C) CI4 D) CCl4

C

41) Atoms of which element, indicated by letter on the periodic table, would be expected to have the most negative value of E ea? A) A B) B C) C D) D

C

42) Which of the above pictures best represents a solid ionic compound? A) picture (a) B) picture (b) C) picture (c) D) picture (d)

C

48) What is the likely formula for the binary compound formed from the elements represented by letters A and D on the periodic table above? A) A2D B) AD C) AD2 D) A2D3

C

5) Consider the following ground state electron configuration: 1s22s22p4. Which of the ions has this ground state electron configuration? A) N+ 1 B) F- 1 C) C- 2 D) O- 2

C

5) What is the bond order of the OO bond in O2? A) 0 B) 1 C) 2 D) 3

C

5) What is the molecular geometry of CH3-? A) T-shaped B) trigonal planar C) trigonal pyramidal D) tetrahedral

C

8) Which molecule contains the most easily broken carbon-carbon bond? A) HC(triple bond)CH B) F2C= CF2 C) H3C-CH3 D) H2C= CH2

C

9) Of the following, which element has the highest first ionization energy? A) krypton B) argon C) helium D) neon

C

1) Based on VSEPR theory, which should have the smallest XAX bond angle? A) 5 piece B) 3 piece w/ double bonds C) 4 piece D) 3 piece w/ single bonds

D

10) A reactive element with a relatively high electronegativity would be expected to have a relatively A) small negative electron affinity and a relatively high ionization energy. B) large negative electron affinity and a relatively low ionization energy. C) small negative electron affinity and a relatively low ionization energy. D) large negative electron affinity and a relatively high ionization energy

D

10) Of the following, which element has the highest first ionization energy? A) iodine B) chlorine C) bromine D) fluorine

D

13) The phosphorus atom in PCl5 would be expected to have a A) 3- charge. B) 3+ charge. C) partial negative (S-) charge. D) partial positive (S+) charge.

D

15) Of the following, which element has the highest first ionization energy? A) C B) Si C) P D) N

D

18) In general, at room temperature A) ionic compounds are all solids, and covalent compounds are liquids or gases. B) covalent compounds are all gases, but ionic compounds may be solids, liquids, or gases. C) ionic compounds are all solids and covalent compounds are all gases. D) ionic compounds are all solids, but covalent compounds may be solids, liquids, or gases.

D

20) A::A represents A) two lone pairs of electrons. B) one lone pair of electrons. C) a quadruple bond. D) a double bond.

D

22) In the reaction of sodium metal with chlorine gas which of the following processes releases energy? A) Na(s) Na(g) B) Cl2(g) 2 Cl(g) C) Na(g) Na+(g) + e- D) Cl(g) + e- Cl-(g)

D

23) How many electrons are in the valence shell of I in IF4-? A) 8 B) 10 C) 14 D) 12

D

25) Calculate the energy change in kJ/mol for the reaction Li+(g) + F-(g) Li(g) + F(g) using the following information: Li(g) Li+(g) + e- +520 kJ/mol F(g) + e- F-(g) -328 kJ/mol A) -848 kJ/mol B) +192 kJ/mol C) +848 kJ/mol D) -192 kJ/mol

D

26) In the electron dot structure of HCN, the bond order of CN is A) 0 B) 1 C) 2 D) 3

D

26) What is the ground-state electron configuration of Se2-? A) [Ar]3d124s24p4 B) [Ar]3d104s24p2 C) [Ar]3d104s24p4 D) [Ar]3d104s24p6

D

27) Consider Li+, F-, and O2-. Which ratio should be the largest? A) (radius Li+)/(radius O2-) B) (radius Li+)/(radius F-) C) (radius F-)/(radius Li+) D) (radius O2-)/(radius Li+)

D

27) NO2- is be expected to have A) one single and one double bond. B) two single bonds. C) two double bonds. D) two identical bonds intermediate between a single and a double bond.

D

29) In the best Lewis structure for CO2, what is the formal charge on the C atom? A) +2 B) -1 C) +1 D) 0

D

3) Which is the longest bond? A) N-H B) N=N C) N(triple bond)N D) N-N

D

30) Which element, indicated by letter on the periodic table above, has a 1+ ion with the electron configuration [Xe]6s2 4f14 5d10? A) A B) B C) C D) D

D

31) Assign formal charges to each atom in the resonance form for SOCl2 given below. A) 0 for Cl, 0 for S, and 0 for O B) -1 for Cl, -2 for S, and -2 for O C) -1 for Cl, +4 for S, and -2 for O D) 0 for Cl, +1 for S, and -1 for O

D

32) Which electron dot structure for OCN- has a formal charge of -1 on the most electronegative atom? A) 6 dots on N & 2 on O B) 6 dots on N & 2 on C C) 4 dots on N & 4 on O D) 2 dots on N & 6 on O

D

33) Which sphere represents the monatomic anion? A) A B) B C) C D) D

D

34) How many lone pairs are on the Br atom in BrI2-? A) 0 B) 1 C) 2 D) 3

D

36) How many lone pairs in the correct electron dot structure of O3? A) 4 B) 2 C) 3 D) 6

D

4) Which ion has the same electron configuration as Kr? A) Se2- B) Rb+ C) Br- D) All of these

D

41) Based on formal charges, what is the SO bond order in SO42-? A) 2 B) 1.3 C) 1 D) 1.5

D

42) Assign formal charges to all atoms in the following resonance form for HNO3. A) 0 for all atoms B) +1 for N and H, -1 for oxygen (a) and oxygen (c), 0 for oxygen (b) C) +1 for H, -2 for each oxygen, +5 for N D) +1 for N, -1 for oxygen (c), 0 for all other atoms

D

43) Which of the above pictures best represents a gaseous covalent compound? A) picture (a) B) picture (b) C) picture (c) D) picture (d)

D

44) Which salt has the highest lattice energy? A) picture (a) B) picture (b) C) picture (c) D) picture (d)

D

47) What is the likely formula for the binary compound formed from the elements represented by letters A and C on the periodic table above? A) A2C B) AC2 C) A2C3 D) AC

D

50) Which element has the most favorable (most negative) electron affinity? A) Ne B) Be C) K D) I

D

6) What is the F-B-F bond angle in BF3? A) 109.5° B) greater than 120° C) less than 109.5° D) 120°

D

7) Of the following elements, which has the highest electronegativity? A) Ga B) Cd C) Si D) N

D

7) Which ion has the smallest ionic radius? A) I- B) Br- C) Cl- D) F-

D

8) Arrange the ions N3- , O2- , Mg2+ , Na+ , and F- in order of increasing ionic radius, starting with the smallest first. A) N3- , Mg2+ , O2- , Na+ , F- B) N3- , O2- , Mg2+ , F- , Na+ C) N3- , O2- , F- , Na+ , Mg2+ D) Mg2+ , Na+ , F- , O2- , N3-

D

8) What is the smallest bond angle in SF6? A) 109.5° B) 60° C) 120° D) 90°

D

36) Which sphere most likely represents the Mg2+ ion? A) A B) B C) C D) D

A

37) Which of the following are allowed resonance forms of NCS-? 1) 4 dots on N & 4 on S 2) 2 dots on N & 4 on S 3) 6 dots on S & 2 on N A) only 1 B) only 2 C) only 3 D) 1 & 3

A

7) What is the molecular geometry of TeF5-? A) square pyramidal B) octahedral C) trigonal bipyramidal D) seesaw

A

6) Which of the following bonds is expected to be stronger? A) C-C bond with a bond order of 3 B) C-C bond with a bond order of 2 C) C-C bond with a bond order of 1 D) C-C bond with a bond order of 0

A

38) Based on formal charge considerations, the electron- dot structure of CO32- ion has A) three resonance structures involving two single bonds and one double bond. B) two resonance structures involving two single bonds and one double bond. C) three resonance structures involving one single bond and two double bonds. D) two resonance structures involving one single bond and two double bonds.

A

39) How many double and single bonds are in the resonance form for SO2 in which the formal charges on each atom are zero? A) no single bonds and two double bonds B) two single bonds and no double bonds C) one single bond and one double bond D) Each of these is possible.

A

45) Which salt has the lowest lattice energy? A) picture (a) B) picture (b) C) picture (c) D) picture (d)

A

46) Which liberates the most energy? A) Li(g ) + e- Li- (g ) B) Rb(g ) + e- Rb-(g ) C) K(g ) + e- K- (g ) D) Na(g ) + e- Na- (g )

A

6) Which ion has the smallest ionic radius? A) Li+ B) K+ C) Na+ D) Rb+

A

11) Which of the following represents the change in electronic configuration that is associated with the second ionization energy of magnesium? A) [Ne]3s1 [Ne] + e- B) [Ne]3s2 [Ne]3s1 + e- C) [Ne]3s2 + e- [Ne]3s23p1 D) [Ne]3s2 [Ne] + 2 e-

A

12) A nitrogen atom in N2 should have a A) charge of 0. B) partial charge S-. C) charge of 1-. D) partial charge S+.

A

15) The electronegativity for both sulfur and carbon is 2.5. Therefore the compound CS2 would be expected to A) have nonpolar covalent bonds between C and S. B) have polar covalent bonds between C and S. C) be ionic with C as the anion. D) be ionic with C as the cation.

A

16) Which period 3 element has successive first through seventh ionization energies (kJ/mol) of Ei1 = 578; Ei2 = 1,817; Ei3 = 2,745; Ei4 = 11,575; Ei5 = 14,830; Ei6 = 18,376; and Ei7 = 23,293? A) Al B) Cl C) S D) Mg

A

17) Which electron affinity process would liberate the most energy? A) [He] 2s2 2p2 + e- [He] 2s2 2p3 B) [He] 2s2 2p6 + e- [He] 2s2 2p6 3s1 C) [He] 2s2 + e- [He] 2s2 2p1 D) [He] 2s2 2p3 + e- [He] 2s2 2p4

A

19) Which of the following molecules is expected to have the highest melting point? A) NaCl B) Cl2 C) H2 D) CCl4

A

19) Which of these elements has the most favorable (most negative) electron affinity? A) S B) N C) Ca D) Ne

A

28) How many resonance structures are required in the electron- dot structure of CO32- ? A) three B) five C) two D) four

A

28) Which ion has the largest radius? Ca+ 2, Ca+ 1, Br- , K+ A) Br- B) K+ C) Ca+ 2 D) Ca+ 1

A

3) Which of the following three sets consist of atoms or ions with the same electron configuration in the ground state? (I) O2-, Ne, and Mg2+ (II) Ni, Cu+, and Zn2+ (III) Hg, Tl+, and Pb2+ A) (I) and (III) B) all three sets C) (I) D) (II) and (III)

A

32) Which sphere represents the metal atom? 32) A) A B) B C) C D) D

A

35) Identify the fourth-row element X that forms the ion. A) Se B) As C) Ge D) Kr

A

1) Covalent bonding is a A) loss of electrons. B) sharing of electrons. C) transfer of electrons. D) gain of electrons.

B

12) Which of the following atoms with the specified electronic configurations would have the lowest first ionization energy? A) [Ne]3s23p4 B) [Xe]6s1 C) [Xe]6s24f145d106p1 D) [He]2s22p3

B

13) Which ionization process requires the most energy? A) Al2+ (g ) Al3+ (g ) + e- B) Al3+ (g ) Al4+ (g ) + e- C) Al+ (g ) Al2+ (g ) + e- D) Al(g ) Al+ (g ) + e-

B

14) List the elements Na, Ca, Rb, Cl, He in order of decreasing first ionization energy. A) He > Na > Ca > Cl > Rb B) He > Cl > Ca > Na > Rb C) Rb > Ca > Cl > Na > He D) He > Na > Cl > Ca > Rb

B

14) The greater the electronegativity difference between two bonded atoms, the A) greater the covalent character of the bond. B) greater the ionic character of the bond. C) more unstable the bond. D) greater the bond order.

B

16) Element A has an electronegativity of 0.8 and element B has an electronegativity of 3.0. Which statement best describes the bonding in A3B? A) The compound is largely ionic with A as the anion. B) The compound is largely ionic with A as the cation. C) The AB bond is largely covalent with a - on A. D) The AB bond is largely covalent with a + on A.

B

21) Which is the most acceptable electron dot structure for N2H2? A) no dots B) N=N with two dots C) N(triple bond) with two dots D) 4 dots

B

22) How many lone pairs of electrons are on the I atom in IF5? A) 0 B) 1 C) 2 D) 3

B

23) Calculate the energy change for the formation of LiCl(s) from its elements in their standard states and the following tabulated information: Li(s) + 1/2 Cl2(g) LiCl(s) ? Li+(g) + Cl-(g) LiCl(s) -853 kJ/mol Li(s) Li(g) +159.4 kJ/mol 1/2 Cl2(g) Cl(g) +121.7 kJ/mol Cl(g) + e- Cl-(g) -348.6 kJ/mol Li(g) Li+(g) + e- +520.2 kJ/mol A) -627.2 kJ/mol B) -400.3 kJ/mol C) +1305.7 kJ/mol D) +296.9 kJ/mol

B

24) Calculate the energy change for the formation of CaF2(s) from its elements in their standard states and the following information: Ca(s) + F2(g) CaF2(s) ? Ca(s) Ca(g) +179.3 kJ/mol Ca(g) Ca+(g) + e- +589.9 kJ/mol Ca+(g) Ca2+(g) + e- +1145 kJ/mol 1/2 F2(g) F(g) +79.0 kJ/mol F(g) + e- F-(g) -328.0 kJ/mol CaF2(s) Ca2+(g) + 2 F-(g) +2630 kJ/mol A) +4046 kJ/mol B) -1214 kJ/mol C) -3286 kJ/mol D) -965 kJ/mol

B

3) What is the molecular geometry of XeF4? A) square pyramidal B) square planar C) tetrahedral D) seesaw

B

30) Two resonance forms for SOCl2 are given below. Which is favored by the octet rule and which by formal charge considerations? A) II is favored by the octet rule and I by formal charge considerations. B) I is favored by the octet rule and II by formal charge considerations. C) II is favored by the octet rule and by formal charge considerations. D) I is favored by the octet rule and by formal charge considerations.

B

31) Which element, indicated by letter on the periodic table above, has a 3+ ion with the electron configuration [Kr]4d 5? A) A B) B C) C D) D

B

35) Which sphere most likely represents the Na ion? A) A B) B C) C D) D

B

38) Atoms of which element, indicated by letter on the periodic table above, would be expected to have the lowest first ionization energy, E i1? A) A B) B C) C D) D

B

4) Which of the following should be nonlinear? 1) 8 dots 2) 16 dots 3) 18 dots A) only 1 B) only 2 C) only 3 D) 2 & 3

B

24) Elements that can accommodate more than eight electrons in their valence shell occur only in periodic table row A) 4 or lower. B) 2 or lower. C) 3 or lower. D) 5 or lower.

C

20) What is the general trend in ionization energy and electron affinity values? A) Both increase as one traverses a period from left to right and both increase as one descends a group. B) Both decrease as one traverses a period from left to right and both increase as one descends a group. C) Both increase as one traverses a period from left to right and both decrease as one descends a group. D) Both decrease as one traverses a period from left to right and both decrease as one descends a group.

C

1) What is the ground- state electron configuration of the ion Hg2+ ? A) [Xe]4f 145d 86s 2 B) [Xe]4f 145d 106s 26p 2 C) [Xe]4f 145d 10 D) [Xe]4f 145d 106s 2

C

11) The compound CCl4 contains A) polar covalent bonds, with partial negative charges on the C atoms. B) ionic bonds. C) polar covalent bonds, with partial negative charges on the Cl atoms. D) nonpolar covalent bonds

C

17) Based on the indicated electronegativities, arrange the following in order of increasing ionic character: CsBr, LaBr3, PBr3, MgBr2. Element Electronegativity Br 2.8 P 2.1 Mg 1.2 La 1.0 Cs 0.7 A) CsBr, LaBr3, MgBr2, PBr3 B) PBr3, LaBr3, MgBr2, CsBr C) PBr3, MgBr2, LaBr3, CsBr D) CsBr, MgBr2, PBr3, LaBr3

C

18) Which element has the most favorable (most negative) electron affinity? A) N B) Li C) C D) B

C

2) What is the ground- state electron configuration of the ion Cu2+ ? A) [Ar] 4s 2 3d 10 4p 1 B) [Ar] 4s 1 3d 8 C) [Ar] 3d 9 D) [Ar] 4s 2 3d 7

C

2) Which electrostatic forces hold atoms together in a molecule? A) electron-electron forces B) nucleus-nucleus forces C) electron-nucleus forces D) all three forces

C

2) Which of the following should be nonplanar? 1) 16 dots 2) 18 dots 3) 20 dots A) only 1 B) only 2 C) only 3 D) 1 & 3

C

21) An element that has the valence electron configuration 3s 23p 3 belongs to which period and group? A) period 4; group 3A B) period 3; group 3A C) period 3; group 5A D) period 4; group 5A

C