MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 CHE Spring Chapter 8 Homework 8 (Chapter 8: Basic concepts of chemical bonding) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A valid Lewis structure of cannot be drawn without violating the A) CO2 B) SO2 C) ICl5 D) NI3 E) SiF4 1) 2) Of the following, cannot accommodate more than an octet of electrons. A) S B) P C) I D) O E) As 3) Of the molecules below, the bond in is the most polar. A) HF B) HCl C) HI D) HBr E) H2 2) 3) 4) Resonance structures differ by. A) placement of electrons only B) number of electrons only C) placement of atoms only D) number and placement of electrons E) number of atoms only 5) Of the possible bonds between carbon atoms (single, double, and triple),. A) a triple bond is longer than a single bond B) a double bond is longer than a triple bond C) a double bond is stronger than a triple bond D) a single bond is stronger than a triple bond E) a single bond is stronger than a double bond 6) Which of the following names is/are correct for the compound SnCl 4? A) tin (II) chloride and tin (IV) chloride B) tin chloride and tin (II) tetrachloride C) tin chloride D) tin tetrachloride and tin (IV) chloride E) tin (IV) tetrachloride 4) 5) 6) 1

2 7) The Lewis structure of N2H2 shows. A) a nitrogen-nitrogen triple bond B) each nitrogen has one nonbonding electron pair C) each hydrogen has one nonbonding electron pair D) a nitrogen-nitrogen single bond E) each nitrogen has two nonbonding electron pairs 8) Of the bonds below, is the least polar. A) Na, Cl B) Si, Cl C) P, S D) C, F E) Na, S 9) The type of compound that is most likely to contain a covalent bond is. A) one that is composed of a metal from the far left of the periodic table and a nonmetal from the far right of the periodic table B) one that is composed of only nonmetals C) a solid metal D) held together by the electrostatic forces between oppositely charged ions E) There is no general rule to predict covalency in bonds. 10) Most explosives are compounds that decompose rapidly to produce products and a great deal of. A) soluble, heat B) liquid, heat C) gaseous, gases D) gaseous, heat E) solid, gas 11) Using the Born-Haber cycle, the ΔHf of KBr is equal to. A) ΔHf [K (g)] + ΔHf [Br (g)] - I1 - E(Br) + ΔHlattice B) ΔHf [K (g)] + ΔHf [Br (g)] + I1(K) + E(Br) + ΔHlattice C) ΔHf [K (g)] - ΔHf [Br (g)] - I1(K) - E(Br) - ΔHlattice D) ΔH f [K (g)] + ΔH f [Br (g)] + I 1 (K) + E(Br) - ΔH lattice E) ΔHf [K (g)] - ΔHf [Br (g)] + I1(K) - E(Br) + ΔHlattice 12) As the number of covalent bonds between two atoms increases, the distance between the atoms and the strength of the bond between them. A) increases, increases B) decreases, decreases C) increases, decreases D) decreases, increases E) is unpredictable 7) 8) 9) 10) 11) 12) 2

3 13) Based on the octet rule, boron will most likely form a ion. A) B1+ B) B3- C) B2+ D) B2- E) B3+ 14) In the Lewis symbol for a sulfur atom, there are paired and unpaired electrons. A) 2, 2 B) 0, 6 C) 2, 4 D) 5, 1 E) 4, 2 13) 14) 15) The electron configuration [Kr]4d10 represents. A) Sn+2 B) Te+2 C) Rb+1 D) Sr+2 E) Ag+1 16) The central atom in does not violate the A) ICl4 - B) XeF4 C) CF4 D) KrF2 E) SF4 15) 16) 17) In the nitrite ion (NO2 - ),. A) both bonds are the same B) both bonds are single bonds C) both bonds are double bonds D) one bond is a double bond and the other is a single bond E) there are 20 valence electrons 18) Of the atoms below, is the most electronegative. A) Cl B) N C) F D) O E) Br 17) 18) 19) Of the ions below, only has a noble gas electron configuration. A) Cl - B) K - C) S 3- D) O 2+ E) I + 19) 20) The Lewis structure of the CO 3 2- ion is. A) 20) B) 3

4 C) D) E) 21) For resonance forms of a molecule or ion,. A) the observed structure is an average of the resonance forms B) all the resonance structures are observed in various proportions C) one always corresponds to the observed structure D) the same atoms need not be bonded to each other in all resonance forms E) there cannot be more than two resonance structures for a given species 22) Which of the following does not have eight valence electrons? A) Xe B) Ti+4 C) Cl- D) Sr+1 E) Rb+1 23) Which of the following has eight valence electrons? A) Kr B) Cl- C) Ti4+ D) Na + E) all of the above 21) 22) 23) 4

5 24) A valid Lewis structure of cannot be drawn without violating the A) NF3 B) CF4 C) SeF4 D) SiF4 E) PO4 3-25) Bond enthalpy is. A) always zero B) always positive C) sometimes positive, sometimes negative D) always negative E) unpredictable 26) Which of the following has the bonds correctly arranged in order of increasing polarity? A) O F, Be F, Mg F, N F B) Mg F, Be F, N F, O F C) N F, Be F, Mg F, O F D) O F, N F, Be F, Mg F E) Be F, Mg F, N F, O F 27) In ionic bond formation, the lattice energy of ions as the magnitude of the ion charges and the radii. A) increases, increase, increase B) increases, increase, decrease C) decreases, increase, increase D) increases, decrease, increase E) increases, decrease, decrease 24) 25) 26) 27) For the questions that follow, consider the BEST Lewis structures of the following oxyanions: (i) NO2 - (ii)no3 - (iii) SO3 2- (iv)so4 2- (v) BrO3-28) In which of the ions do all X-O bonds (X indicates the central atom) have the same length? A) none B) all C) (i) and (ii) D) (iii) and (v) E) (iii), (iv), and (v) 29) There can be four equivalent best resonance structures of. A) (i) B) (ii) C) (iii) D) (iv) E) (v) 28) 29) 5

6 30) The oxidation number of phosphorus in PF3 is. A) +1 B)-2 C) +2 D) +3 E)-3 31) Of the atoms below, is the least electronegative. A) Ca B) Cl C) F D) Si E) Rb 32) Which of the following names is/are correct for the compound TiO2? A) titanium (IV) dioxide B) titanium oxide C) titanium oxide and titanium (IV) dioxide D) titanium (II) oxide E) titanium dioxide and titanium (IV) oxide 33) Dynamite consists of nitroglycerine mixed with. A) TNT B) damp KOH C) potassium nitrate D) solid carbon E) diatomaceous earth or cellulose 34) Why don't we draw double bonds between the Be atom and the Cl atoms in BeCl2? A) That would give positive formal charges to the chlorine atoms and a negative formal charge to the beryllium atom. B) There aren't enough electrons. C) That would result in more than eight electrons around beryllium. D) That would result in more than eight electrons around each chlorine atom. E) That would result in the formal charges not adding up to zero. 35) Which two bonds are most similar in polarity? A) I Br and Si Cl B) Al Cl and I Br C) B F and Cl F D) O F and Cl F E) Cl Cl and Be Cl 36) The chloride of which of the following metals should have the greatest lattice energy? A) sodium B) potassium C) rubidium D) lithium E) cesium 30) 31) 32) 33) 34) 35) 36) 6

7 37) A valid Lewis structure of cannot be drawn without violating the A) CO2 B) ClF3 C) CCl4 D) PCl3 E) SO3 37) 38) Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate an octet? A) B B) O C) C D) H E) N 39) Given that the average bond energies for C-H and C-Br bonds are 413 and 276 kj/mol, respectively, the heat of atomization of bromoform (CHBr 3 ) is kj/mol. A) 689 B)-1378 C) 1241 D) 1378 E) ) A valid Lewis structure of cannot be drawn without violating the A) SO2 B) SO3 2- C) CF4 D) BeH2 E) NF3 38) 39) 40) 7