AP Chem

Bonding Test

1. Which of the following bonds is expected to be the most polar?

A. C-Si B. C-N C. O-C D. S-C E. H-C

2. For which of the following molecules may we draw both polar and non-polar Lewis structures?

A. CHCl3 B. NH3 C. BF3 D. SF2Cl4 E. PCl5

3. Which of the following has the fewest pi bonds and is non-polar?

A. HCCH B. CO2 C. CO32- D. N2 E. SO2

4. The SF5- ion has a square pyramidal structure. The hybridization of the orbitals in sulfur is:

A. sp3d B. sp C. sp3d2 D. sp3 E. sp2

5. Which of the following is NOT a linear structure?

A. I2 B. I3- C. CO2 D. H2S E. HCCH

6. In which of the following are the two items NOT properly related?

A. sp3 and 109.5

B. trigonal planar and 120

C. octahedral and sp3d

D. sp and 180

E. square planar and sp3d2

7. How many resonance structures are possible for the molecule SO3?

A. None B. 2 C. 3 D. 4 E. 4/3

8. Which of the following has a nonbonding pair of electrons on the central atom?

A. BCl3

B. NH3

C. CCl2Br2

D. PF5

E. SO42-

9. Which of the following is true when the carbon to carbon bonds in HCCH and H2CCH2 are compared?

A. The triple bond is shorter than the double bond?

B. The double bond energy is lower than the triple bond energy.

C. Both are composed of sigma and pi bonds.

D. Both involve hybrid orbitals.

E. All of the above.

10. How many electrons are available to construct the Lewis structure of sulfite ion?

A. 24 B. 18 C. 26 D. 22 E. 20

11. Which of these bond angles is not expected in a molecule?

A. 60 B. 90 C. 109.5 D. 120 E. sp3d2

12. Sulfur forms the following molecules: SO2, SF6, SCl4, SCl2. Which form of hybridization is NOT represented by these molecules?

A. sp B. sp2 C. sp3 D. sp3d2

13. Which theory predicts the shape of molecules?

A. Molecular orbital (MO) theory

B. Valence bond (VB) theory

C. The localized electron model

D. VSEPR theory

E. Atomic theory

14. Which of the following is expected to have the largest dipole moment?

A. CH4 B. CO2 C. SF6 D. HCN E. Cl-

15. Which of the following has more than one pi bond?

A. CO2 B. SO2 C. NH3 D. C3H6 E. CH2O

16-19 refer to the following:

A. Hydrogen bonding

B. Molecular crystals

C. Ionic bonding’

D. Covalent bonding

E. London forces (van der Waals forces)

_____16. C-H bonds involve this.

_____17. It describes the solid form of CO2.

_____18. It is used to explain why nonpolar substances can be condensed to liquids.

_____19. It is, in general the strongest inter- and intra- molecular force.

20. Which of the following has a Lewis structure that contains a double bond?

A. NH3 B. NO3- C. CH4 D. Cl2 E. BF3

21. Which of the following does not form hydrogen bonds?

A. HCN B. HF C. CH3NH2 D. CH3COOH E. ClCH2OH

22. Which best explains why CO2 is nonpolar?

A. Ionic bonding

B. MO theory

C. VSEPR

D. Electronegativity

E. Hybridization

23. Which of the following has 2 different bond angles in the same molecule?

A. Tetrahedron

B. Linear

C. Trigonal bipyramid

D. Octahedron

E. Trigonal planar

24. The shortest bond would be present in which of the following species:

A. I2 B. CO C. CCl4 D. O22- E. SCl2

25. Which explains why the two bonds in O3 are equal in length?

A. Resonance

B. VSEPR

C. Hybridization

D. Electronegativity

E. MO theory

26. Which of the following substances has ionic, sigma, and pi bonds?

A. Na2CO3 B. HClO2 C. H2O D. CO2 E. NaCl

27-32 refer to the following:

A. C2 B. F2 C. B2 D. O2 E. Ne2

_____27. The paramagnetic molecule with a bond order of two.

_____28. The diamagnetic molecule with no antibonding electrons.

_____29. The paramagnetic molecule with antibonding electrons.

_____30. Less stable than the element’s two other well known allotropes.

_____31. Very reactive, but stable enough to exist until it contacts other substances.

_____32. Too unstable to form.

33. Rationalize the difference in energy for these two reactions:

NCl3 = NCl2 + Cl Delta H = 375 kJ/mol

ONCl = NO + Cl Delta H= 158 kJ/mol

34. Explain the relative values of the melting points of these substances. You do not need to discuss crystal structure or packing issues.

Substance: Meltiing point ©

SrS >2000

KCl 770

H2O 0

H2S -85.5

CH4 -182

35. Here is a table of some thermodynamic values:

Substance: Enthalpy of formation: (kJ/mol)

PCl3 -287

O2 0

POCl3 -542.2

Bond: Bond energy (kJ/mol)

P-Cl 331

O=O 498

O-O 204

A. Determine the enthalpy change for the above reaction.

B. Estimate the PO bond energy.

C. Is the PO bond double or single? Give two explanations of why you think the PO bond is double or single. You can write, draw, make a model with scrap paper, finger paint, etc.

36. Use appropriate chemical principles to account for each of the following observations. In each part, your response must include specific information about both substances.

  1. At 25C and 1atm, F2 is a gas and I2 is a solid.
  2. The melting point of NaF is 993C while the melting point of CsCl is 645C.
  3. The shape of ICl4- is square planar while BF4- is tetrahedral.
  4. Ammonia, NH3 is very soluble in water while phosphine, PH3, is not.