AP Chem U5 Test

The electron-dot structure (Lewis structure) for which of the following molecules would have two unshared pairs of electrons on the central atom? A. H2S B. NH3 C. CH4 D. HCN E. CO2

A. H2S

Which of the following has the bonds arranged in order of decreasing polarity? A. H−F > N−F > F−F B. H−I > H−Br > H−F C. O−N > O−S > O−Te D. Sb−I > Sb−Te > Sb−C

A. H−F > N−F > F−F

Morse Potential Diagram Given The potential energy of a system of two atoms as a function of their internuclear distance is shown in the diagram above. Which of the following is true regarding the forces between the atoms when their internuclear distance is x? A. The attractive and repulsive forces are balanced, so the atoms will maintain an average internuclear distance x. B. There is a net repulsive force pushing the atoms apart, so the atoms will move further apart. C. There is a net attractive force pulling the atoms together, so the atoms will move closer together. D. It cannot be determined whether the forces between atoms are balanced, attractive, or repulsive, because the diagram shows only the potential energy

A. The attractive and repulsive forces are balanced, so the atoms will maintain an average internuclear distance x.

The melting point of MgO is higher than that of NaF. Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+. II. O2- is more negatively charged than F-. III. The O2- ion is smaller than the F- ion. A. II only B. I and II only C. I and III only D. II and III only E. I, II, and III

B. I and II only

Resonance is most commonly used to describe the bonding in molecules of which of the following? A. CO2 B. O3 C. H2O D. CH4 E. SF6

B. O3

Which of the following molecules has an angular (bent) geometry that is commonly represented as a resonance hybrid of two or more electron-dot structures? A. CO2 B. O3 C. CH4 D. BeF2 E. OF2

B. O3

Forms monatomic ions with 2- charge in solutions A. F B. S C. Mg D. Ar E. Mn

B. S

The BF3 molecule is nonpolar, whereas the NF3 molecule is polar. Which of the following statements accounts for the difference in polarity of the two molecules? A. In NF3, each F is joined to N with multiple bonds, whereas in BF3 , each F is joined to B with single bonds. B. N — F bonds are polar, whereas B — F bonds are nonpolar. C. NF3 is an ionic compound, whereas BF3 is a molecular compound. D. Unlike BF3, NF3 has a nonplanar geometry due to an unshared pair of electrons on the N atom.

D. Unlike BF3, NF3 has a nonplanar geometry due to an unshared pair of electrons on the N atom.

Which of the following arranges the molecules N2, O2, and F2 in order of their bond enthalpies, from least to greatest? A. F2 < O2 < N2 B. O2 < N2 < F2 C. N2 < O2 < F2 D. N2 < F2 < O2

A. F2 < O2 < N2

The question refers to the following species. (A) H2O (B) NH3 (C) BH3 (D) CH4 (E) SiH4 Has two lone pairs of electrons A. H2O B. NH3 C. BH3 D. CH4 E. SiH4

A. H2O

The question refers to the following species. (A) H2O (B) NH3 (C) BH3 (D) CH4 (E) SiH4 Has a central atom with less than an octet of electrons A. H2O B. NH3 C. BH3 D. CH4

C. BH3

The diagram above shows two resonance structures for a molecule of C6H6. The phenomenon shown in the diagram best supports which of the following claims about the bonding in C6H6 ? A. In the C6H6 molecule, all the bonds between the carbon atoms have the same length. B. Because of variable bonding between its carbon atoms, C6H6 is a good conductor of electricity. C. The bonds between carbon atoms in C6H6 are unstable, and the compound decomposes quickly. D. The C6H6 molecule contains three single bonds between carbon atoms and three double bonds between carbon atoms.

A. In the C6H6 molecule, all the bonds between the carbon atoms have the same length.

Which of the following molecules has the shortest bond length? A. N2 B. O2 C. Cl2 D. Br2 E. I2

A. N2

In the following diagrams, elements are represented by X and Z, which form molecular compounds with one another. Which diagram represents a molecule that has a bent molecular geometry? A. The figure presents a Lewis diagram of a molecule. Atom X is bonded to atom Z by a single bond. Atom Z has three nonbonding pairs of electrons. B. The figure presents a Lewis diagram of a molecule. Atom X is bonded to 2 Z atoms, directly to the left and right, by single bonds. Atom X has two nonbonding pairs of electrons. C. The figure presents a Lewis diagram of a molecule. Atom X is bonded to 2 Z atoms, directly to the left and right, by single bonds. The two Z atoms each have three nonbonding pairs of electrons. D. The figure presents a Lewis diagram of a molecule. Atom X is bonded to 2 Z atoms, directly to the left and right, by double bonds. The two Z atoms each have two nonbonding pairs of electrons.

B. The figure presents a Lewis diagram of a molecule. Atom X is bonded to 2 Z atoms, directly to the left and right, by single bonds. Atom X has two nonbonding pairs of electrons.

Which of the following Lewis electron-dot diagrams represents the molecule that contains the smallest bond angle? A. The molecule has 4 F atoms each connected with a single bond to the same C atom. Each F atom has 3 pairs of nonbonding electrons. B. The molecule has 3 F atoms each connected with a single bond to the same N atom. The N atom has 1 pair of nonbonding electrons. Each F atom has 3 pairs of nonbonding electrons. C. The molecule has 3 O atoms connected to the same S atom. One O atom is connected with a double bond to the S atom and the other two O atoms are each connected with a single bond to the S atom. The double-bonded O atom has 2 pairs of nonbonding electrons. Each of the single-bonded O atoms has 3 pairs of nonbonding electrons. D. The molecule has 2 O atoms connected to the same S atom. One O atom is connected with a single bond to the S atom and the other O atom is connected with a double bond to the S atom. The S atom has 1 pair of nonbonding electrons. The double-bonded O atom has 2 pairs of nonbonding electrons. The single-bonded O atom has 3 pairs of nonbonding electrons.

B. The molecule has 3 F atoms each connected with a single bond to the same N atom. The N atom has 1 pair of nonbonding electrons. Each F atom has 3 pairs of nonbonding electrons.

Which of the following is a nonpolar molecule that contains polar bonds? A. F2 B. CHF3 C. CO2 D. HCl E. NH3

C. CO2

Two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. Which of the following is the most valid scientific claim that can be made about the compound? A. It has the formula XZ2. B. It does not dissolve in water. C. It contains ionic bonds. D. It contains covalent bonds.

C. It contains ionic bonds.

The lattice energy of a salt is related to the energy required to separate the ions. For which of the following pairs of ions is the energy that is required to separate the ions largest? (Assume that the distance between the ions in each pair is equal to the sum of the ionic radii.) A. Na+(g) and Cl−(g) B. Cs+(g) and Br−(g) C. Mg2+(g) and O2−(g) D. Ca2+(g) and O2−(g)

C. Mg2+(g) and O2−(g)

Which of the molecules represented below contains carbon with sp2 hybridization? A. CH4 B. CH2Cl2 C. C2H6 D. C2H2Cl2 E. C2H4Cl2

D. C2H2Cl2

Which of the following molecules contains polar covalent bonds but is a nonpolar molecule? A. CH3Cl B. CH2Cl2 C. NH3 D. CCl4 E. N2

D. CCl4

Lewis electron-dot diagrams for CO2 and SO2 are given above. The molecular geometry and polarity of the two substances are A. the same because the molecular formulas are similar B. the same because C and S have similar electronegativity values C .different because the lone pair of electrons on the S atom make it the negative end of a dipole D. different because S has a greater number of electron domains (regions of electron density) surrounding it than C has

D. different because S has a greater number of electron domains (regions of electron density) surrounding it than C has

1s2 2s2 2p6 3s2 3p3 Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed with magnesium, Mg, is A. MgX B. Mg2X C. MgX2 D. MgX3 E. Mg3X2

E. Mg3X2

Which of the following complete Lewis diagrams represents a molecule containing a bond angle that is closest to 120°? A. The figure presents a Lewis diagram. A Carbon atom is bonded to two Oxygen atoms, located to the left and right, with double bonds. Each Oxygen atom has two nonbonding pairs of electrons. B. The figure presents a Lewis diagram. A Carbon atom is bonded to 4 Hydrogen atoms, located directly to the left, to the right, above, and below it, with single bonds. C. The figure presents a Lewis diagram. A Nitrogen atom is bonded to 3 Hydrogen atoms, located directly to the left, to the right, and above it, by single bonds. The Nitrogen atom has one nonbonding pair of electrons. D.The figure presents a Lewis diagram. There is a Carbon atom bonded to 3 Hydrogen atoms, located directly to the left, above, and below it, by single bonds. The Carbon atom is also bonded to another Carbon atom, located directly to its right, by a single bond. The second Carbon is bonded to two Oxygen atoms, located directly above and to the right of it. The Oxygen atom above is bonded to the carbon atom by a double bond, and the oxygen atom to the right is bonded to the carbon atom by a single bond. Each oxygen atom has two nonbonding pairs of electrons. The oxygen atom on the right is also bonded to a hydrogen atom by a single bond.

D.The figure presents a Lewis diagram. There is a Carbon atom bonded to 3 Hydrogen atoms, located directly to the left, above, and below it, by single bonds. The Carbon atom is also bonded to another Carbon atom, located directly to its right, by a single bond. The second Carbon is bonded to two Oxygen atoms, located directly above and to the right of it. The Oxygen atom above is bonded to the carbon atom by a double bond, and the oxygen atom to the right is bonded to the carbon atom by a single bond. Each oxygen atom has two nonbonding pairs of electrons. The oxygen atom on the right is also bonded to a hydrogen atom by a single bond.

Which of the following Lewis diagrams best represents the bonding in the N2O molecule, considering formal charges? A. The figure presents a Lewis diagram. There is a Nitrogen atom bonded to another Nitrogen atom and an oxygen atom with double bonds. The outer Nitrogen atom and the oxygen atom each have two nonbonding pairs of electrons. B. The figure presents a Lewis diagram. There is a Nitrogen atom bonded to another Nitrogen atom with a triple bond and to an oxygen atom with a single bond. The outer Nitrogen atom has one nonbonding pair of electrons and the Oxygen atom has three nonbonding pairs of electrons. C. The figure presents a Lewis diagram. There is a Nitrogen atom bonded to another Nitrogen atom with a single bond and to an Oxygen atom with a double bond. The outer Nitrogen atom has three nonbonding pairs of electrons and the central nitrogen atom has one nonbonding pair of electrons. The Oxygen atom has two nonbonding pairs of electrons. D. The figure presents a Lewis diagram. There is an oxygen atom bonded to two nitrogen atoms, one with a single bond and one with a double bond. The Nitrogen atom connected with a single bond has three nonbonding pairs of electrons. The Nitrogen atom connected with a double bond has two nonbonding pairs of electrons.

Look this one up on AP U5 T7 B. The figure presents a Lewis diagram. There is a Nitrogen atom bonded to another Nitrogen atom with a triple bond and to an oxygen atom with a single bond. The outer Nitrogen atom has one nonbonding pair of electrons and the Oxygen atom has three nonbonding pairs of electrons.

Which of the following molecules contains exactly three sigma (σ) bonds and two pi (π) bonds? A. C2H2 B. CO2 C. HCN D. SO3 E. N2

A. C2H2

Chart with Element and Electronegativities Given On the basis of the information above, which of the following arranges the binary compounds in order of increasing bond polarity? A. CH4 < SiCl4 < SF4 B. CH4 < SF4 < SiCl4 C. SF4 < CH4 < SiCl4 D. SiCl4 < SF4 < CH4

A. CH4 < SiCl4 < SF4

Has molecules with a pyramidal shape A. NH3(g) B. BH3(g) C. H2(g) D. H2S(g) E. HBr(g)

A. NH3(g)

Boiling Point Table and Ionic Radii Table Given Based on the data in the tables above, which of the following statements provides the best prediction for the boiling point of NaCl ? A. NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF . B. NaCl will have a boiling point between that of NaF and MgO because the covalent character of the bonds in NaCl is intermediate between that of MgO and NaF. C. NaCl will have a higher boiling point than MgO because the ions are spaced farther apart in NaCl . D. NaCl will have a higher boiling point than MgO because the energy required to transfer electrons from the anion to the cation is larger in NaCl than in MgO .

A. NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF .

The atom that contains exactly two unpaired electrons A. S B. Ca C. Ga D. Sb E. Br

A. S

Which of the following statements, if true, would support the claim that the NO3− ion, represented above, has three resonance structures? A. The NO3− ion is not a polar species. B. The oxygen-to-nitrogen-to-oxygen bond angles are 90°. C. One of the bonds in NO3− is longer than the other two. D. One of the bonds in NO3− is shorter than the other two.

A. The NO3− ion is not a polar species.

Morse Potential Diagram Given The potential energy as a function of internuclear distance for three diatomic molecules, X2, Y2, and Z2, is shown in the graph above. Based on the data in the graph, which of the following correctly identifies the diatomic molecules, X2, Y2, and Z2? A. X2 Y2 Z2 H2 N2 O2 B. X2 Y2 Z2 H2 O2 N2 C. X2 Y2 Z2 N2 O2 H2 D. X2 Y2 Z2 O2 H2 N2

A. X2 Y2 Z2 H2 N2 O2

Reaction 1: CaC2(s) + 2 H2O(l) → C2H2(g) + Ca(OH)2(s) Reaction 2: NaOCl(aq) + 2 HCl(aq) → Cl2(g) + NaCl(aq) + H2O(l) Reaction 3: C2H2(g) + Cl2(g) → C2H2Cl2(g) When Reaction 3 occurs, does the hybridization of the carbon atoms change? A. Yes; it changes from sp to sp2. B. Yes; it changes from sp to sp3. C. Yes; it changes from sp2 to sp3. D. No; it does not change

A. Yes; it changes from sp to sp2.

H - C ≡ C - H What is the hybridization of the carbon atoms in a molecule of ethyne, represented above? A. sp B. sp2 C.s p3 D. dsp2 E. d2sp

A. sp

The geometry of the SO3 molecule is best described as A. trigonal planar B. trigonal pyramidal C. square pyramidal D. bent E. tetrahedral

A. trigonal planar

Atoms of Mg combine with atoms of F to form a compound. Atoms of which of the following elements combine with atoms of F in the same ratio? A. Li B. Ba C. Al D. Cl E. Ne

B. Ba

The structural formula of the glycinium cation is shown above. Arrows indicate the pKa values for the labile protons in the molecule. Which of the following is true about the geometry of the glycinium cation? A. The leftmost C atom and all the atoms directly bonded to it lie in the same plane. B. Both C atoms and both O atoms lie in the same plane. C. The N−C−C bond angle is 180°. D. The geometry around the N atom is planar

B. Both C atoms and both O atoms lie in the same plane.

The following questions refer to the below molecules: (A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 The molecule with the largest dipole moment A. CO2 B. H2O C. CH4 D. C2H4 E. PH3

B. H2O

The question refers to the following species. (A) H2O (B) NH3 (C) BH3 (D) CH4 (E) SiH4 Has a trigonal-pyramidal molecular geometry A. H2O B. NH3 C .BH3 D. CH4 E. SiH4

B. NH3

For which of the following molecules are resonance structures necessary to describe the bonding satisfactorily? A. H2S B. SO2 C. CO2 D. OF2 E. PF3

B. SO2

Refer to the following gaseous molecules: (A) BeCl2 (B) SO2 (C) N2 (D) O2 (E) F2 Is a polar molecule A. BeCl2 B. SO2 C. N2 D. O2 E. F2

B. SO2

Refer to the following gaseous molecules: (A) BeCl2 (B) SO2 (C) N2 (D) O2 (E) F2 Is best represented by two or more resonance forms A. BeCl2 B. SO2 C. N2 D. O2 E. F2

B. SO2

Morse Potential Diagram Given Which of the following can be inferred from the diagram above that shows the dependence of potential energy on the internuclear distance between two atoms? A. The atoms form a bond with a bond length of 25pm. B. The atoms form a bond with a bond length of 75pm. C. The net force between the atoms is attractive at 25pm. D. The net force between the atoms is attractive at 75pm.

B. The atoms form a bond with a bond length of 75pm.

The elements C and Se have the same electronegativity value, 2.55. Which of the following claims about the compound that forms from C and Se is most likely to be true? A. The carbon-to-selenium bond is unstable. B. The carbon-to-selenium bond is nonpolar covalent. C. The compound has the empirical formula CSe. D. A molecule of the compound will have a partial negative charge on the carbon atom.

B. The carbon-to-selenium bond is nonpolar covalent.

Which of the following Lewis electron-dot diagrams represents the molecule that is the most polar?

B. The ones with BrF

The structural formula of the glycinium cation is shown above. Arrows indicate the pKa values for the labile protons in the molecule. What is the approximate H−O−C bond angle in the glycinium cation? A. 180° B. 120° C. 105° D. 90°

C. 105°

A Lewis diagram for the molecule C2H4 is shown above. In the actual C2H4 molecule, the H-C-H bond angles are closest to A. 90° B. 109.5° C. 120° D. 180°

C. 120°

The question refers to the following species. (A) H2O (B) NH3 (C) BH3 (D) CH4 (E) SiH4 Is predicted to have the largest bond angle A. H2O B. NH3 C. BH3 D. CH4 E. SiH4

C. BH3

Which of the following molecules contains only single bonds? A. CH3COOH B. CH3CH2COOCH3 C. C2H6 D. C6H6 E. HCN

C. C2H6

Which of the following is an isomer of CH3OCH3 ? A. CH3CH3 B. CH3COOH C. CH3CH2OH D. CH3CH2CH3 E. CH3CH2OCH2CH3

C. CH3CH2OH

Refer to the following compounds. (A) CH3CH2CH2CH3 (B) CH3CH2CH2OH (C) CH3COCH3 (D) CH3COOH (E) CH3CH2CH2NH2 Is isomeric with CH3CH2CHO A. CH3CH2CH2CH3 B. CH3CH2CH2OH C. CH3COCH3 D. CH3COOH E. CH3CH2CH2NH2

C. CH3COCH3

Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 Contains 1 sigma (σ) and 2 pi (π) bonds A. Li2 B. B2 C. N2 D. O2 E. F2

C. N2

Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 Has the largest bond-dissociation energy A. Li2 B. B2 C. N2 D. O2 E. F2

C. N2

Refer to the following gaseous molecules: (A) BeCl2 (B) SO2 (C) N2 (D) O2 (E) F2 Is the molecule in which the intramolecular forces are strongest A. BeCl2 B. SO2 C. N2 D. O2 E. F2

C. N2

Of the following single bonds, which is the LEAST polar? A. N—H B. H—F C. O—F D. I—F E. O—H

C. O—F

All the chlorides of the alkaline earth metals have similar empirical formulas, as shown in the table above. Which of the following best helps to explain this observation? A. Cl2(g) reacts with metal atoms to form strong, covalent double bonds. B. Cl has a much greater electronegativity than any of the alkaline earth metals. C. The two valence electrons of alkaline earth metal atoms are relatively easy to remove. D. The radii of atoms of alkaline earth metals increase moving down the group from Be to Ra.

C. The two valence electrons of alkaline earth metal atoms are relatively easy to remove.

N2 molecules absorb ultraviolet light but not visible light. I2 molecules absorb both visible and ultraviolet light. Which of the following statements explains the observations? A. More energy is required to make N2 molecules vibrate than is required to make I2 molecules vibrate. B. More energy is required to remove an electron from an I2 molecule than is required to remove an electron from a N2 molecule. C. Visible light does not produce transitions between electronic energy levels in the N2 molecule but does produce transitions in the I2 molecule. D. The molecular mass of I2 is greater than the molecular mass of N2.

C. Visible light does not produce transitions between electronic energy levels in the N2 molecule but does produce transitions in the I2 molecule.

Which of the following best helps explain why the electronegativity of Cl is less than that of F? A. The mass of the Cl atom is greater than the mass of the F atom. B. The Cl nucleus contains more protons than the F nucleus contains. C. When Cl and F form bonds with other atoms, the Cl bonding electrons are more shielded from the positive Cl nucleus than the F bonding electrons are shielded from the positive F nucleus. D. Because Cl is larger than F, the repulsions among electrons in the valence shell of Cl are less than the repulsions among electrons in the valence shell of F.

C. When Cl and F form bonds with other atoms, the Cl bonding electrons are more shielded from the positive Cl nucleus than the F bonding electrons are shielded from the positive F nucleus.

Diagram of structures given Solid carbon tetrachloride, CCl4(s), is represented by the diagram above. The attractions between the CCl4 molecules that hold the molecules together in the solid state are best identified as A. polar covalent bonds B. nonpolar covalent bonds C. intermolecular attractions resulting from temporary dipoles D. intermolecular attractions resulting from permanent dipoles

C. intermolecular attractions resulting from temporary dipoles

C2H6 Lewis structure given The hybridization of the carbon atoms in the molecule represented above can be described as A. sp B.s p2 C. sp3 D. dsp2 E. d2sp

C. sp3

starts with C2H4 + 03 goes to C2H4O3 all together In the reaction represented above, what is the hybridization of the C atoms before and after the reaction occurs? A. Before After sp sp2 B. Before After sp sp3 C. Before After sp2 sp D. Before After sp2 sp3

D. Before After sp2 sp3

Picture Of Beaker X,Y,Z given Beaker X and beaker Y each contain 1.0 L of solution, as shown above. A student combines the solutions by pouring them into a larger, previously empty beaker Z and observes the formation of a white precipitate. Assuming that volumes are additive, which of the following sets of solutions could be represented by the diagram above? Beaker X | Beaker Y| Beaker Z A. 2.0 M AgNO3 | 2.0 M MgCl2 | 4.0 M Mg(NO3)2 and AgCl(s) B. 2.0 M AgNO3 | 2.0 M MgCl2 | 2.0 M Mg(NO3)2 and AgCl(s) C. 2.0 M AgNO3 | 1.0 M MgCl2 | 1.0 M Mg(NO3)2 and AgCl(s) D. 2.0 M AgNO3 | 1.0 M MgCl2 | 0.50 M Mg(NO3)2 and AgCl(s)

D. 2.0 M AgNO3 | 1.0 M MgCl2 | 0.50 M Mg(NO3)2 and AgCl(s)

(A) Cs (B) Ag (C) Pb (D) Br (E) Se Has the highest electronegativity A. Cs B. Ag C. Pb D. Br E. Se

D. Br

If Na reacts with chlorine to form NaCl, which of the following elements reacts with Na to form an ionic compound in a one-to-one ratio, and why? A. K, because it is in the same group as Na. B. Mg, because its mass is similar to that of Na. C. Ar, because its mass is similar to that of Cl. D. Br, because it has the same number of valence electrons as Cl.

D. Br, because it has the same number of valence electrons as Cl.

In which of the following processes are covalent bonds broken? A. I2(s) → I2(g) B. CO2(s) → CO2(g) C. NaCl(s) → NaCl(l) D. C(diamond) → C(g) E. Fe(s) → Fe(l)

D. C(diamond) → C(g)

Which of the following molecules is nonpolar but has polar covalent bonds? A. N2 B. H2O2 C. H2O D. CCl4 E. CH2Cl

D. CCl4

Particle diagrams of Two different particle Boxes Given Equal volumes of solutions in two different vessels are represented above. If the solution represented in vessel 1 is KCl(aq), then the solution represented in vessel 2 could be an aqueous solution of A. KCl with the same molarity as the solution in vessel 1 B. KCl with twice the molarity of the solution in vessel 1 C. CaCl2 with the same molarity as the solution in vessel 1 D. CaCl2 with twice the molarity of the solution in vessel 1

D. CaCl2 with twice the molarity of the solution in vessel 1

Of the following molecules, which has the largest dipole moment? A. CO B. CO2 C. O2 D. HF E. F2

D. HF

Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 Has a bond order of 2 A. Li2 B. B2 C. N2 D. O2 E. F2

D. O2

Which of the following scientific claims about the bond in the molecular compound HF is most likely to be true? A. There is a partial negative charge on the H atom. B. Electrons are shared equally between the H and F atoms. C. The bond is extremely weak. D. The bond is highly polar.

D. The bond is highly polar.

Lewis diagrams of molecules of three different hydrocarbons are shown above. Which of the following claims about the molecules is best supported by the diagrams? A. All the atoms in molecule 1 lie in one plane. B. All the molecules have the same empirical formula. C. The C-C-C bond angle in molecule 2 is close to 180°. D. The strongest carbon-to-carbon bond occurs in molecule 3.

D. The strongest carbon-to-carbon bond occurs in molecule 3.

NH3 reacts with BF3 to form a single species. Which of the following structural diagrams is the most likely representation of the product of the reaction? A. The structural diagram has a chain of single atoms each connected with a single bond. From left to right the atoms are as follows: H, N, H, F, B, F. The N atom is connected to another H atom with a single bond, and the B atom is connected to another F atom with a single bond. B. The structural diagram has a chain of single atoms each connected with a single bond. From left to right the atoms are as follows: H, N, H, F, B, F. The N atom is connected to another H atom with a single bond, and the B atom is connected to two additional F atoms, each with a single bond. C. The structural diagram has a chain of single atoms each connected with a single bond. From left to right the atoms are as follows: H, N, H, F, B, F. The N atom is connected to two additional H atoms, each with a single bond, and the B atom is connected to another F atom with a single bond. D. The structural diagram has a chain of single atoms each connected with a single bond. From left to right the atoms are as follows: H, N, H, F, B, F. The N atom is connected to two additional H atoms, each with a single bond, and the B atom is connected to two additional F atoms, each with a single bond.

D. The structural diagram has a chain of single atoms each connected with a single bond. From left to right the atoms are as follows: H, N, H, F, B, F. The N atom is connected to two additional H atoms, each with a single bond, and the B atom is connected to two additional F atoms, each with a single bond.

Pi (π) bonding occurs in each of the following species EXCEPT A. CO2 B. C2H4 C. CN- D. C6H6 E. CH4

E. CH4

Of the following compounds, which is the most ionic? A. SiCl4 B. BrCl C. PCl3 D. Cl2O E. CaCl2

E. CaCl2

Which of the following compounds contains both ionic and covalent bonds? A. SO3 B. C2H5OH C. MgF2 D. H2S E. NH4Cl

E. NH4Cl

Which of the following has a zero dipole moment? A. HCN B. NH3 C. SO2 D. NO2 E. PF5

E. PF5

The following questions refer to the below molecules: (A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 The molecule that has trigonal pyramidal geometry A. CO2 B. H2O C. CH4 D. C2H4 E. PH3

E. PH3