Download Questions 1- 4 refer to this molecule. 1. What is the hybridization

Chemistry 111‐2010 9 AM Section NAME: _____________________ Exam #3 Questions 1‐ 4 refer to this molecule. 1. What is the hybridization used by the O atom (labeled “A”)? a. sp b. sp2 c. sp3 d. sp3d e sp3d2 2. Based on number of structural pairs, what is the ideal C‐N‐H bond angle referred to with the “B”? a. 90o b. 109.5o c. 120o d. 180o 3. Describe what orbitals are involved in the C=O double bond. *** all these answers are wrong; correct **answer is a sigma bond between two sp2 hybrid orbitals and a pi bond between two p orbitals a. a sigma bond between an sp3 hybrid orbital and an sp hybrid orbital b. a sigma bond between an sp3 hybrid orbital and an s orbital c. a sigma bond between an sp2 hybrid orbital and an s orbital d. a pi bond between an sp3 hybrid orbital and an sp hybrid orbital e. this is an antibond 4. Describe what orbitals are involved in the C‐H bond labeled “D.” a. a sigma bond between an sp3 hybrid orbital and an sp hybrid orbital b. a sigma bond between an sp3 hybrid orbital and an s orbital c. a sigma bond between an sp2 hybrid orbital and an s orbital d. a pi bond between an sp3 hybrid orbital and an sp hybrid orbital e. this is an antibond For questions 5‐8 the answer choices are: a. linear b. trigonal planar c. tetrahedral d. trigonal bipyramidal e. octahedral f. bent g. trigonal pyramidal h. see‐saw i. T‐ shaped j. square pyramidal 5. What is the electron‐pair geometry of SO3? 6. What is the electron‐pair geometry of PF3? 7. What is the molecular geometry of CH2O? The O and two H’s are bonded to C. 8. What is the molecular geometry of SF4? ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ 9. Which bond is most polar? a. C–C b. C–O c. N–N d. N–O 10. Which of the following molecules is/are nonpolar? a. NH3 b. CH4 c. O2 and CH4 d. NH3 and CH2O e. CH2O and O2 11. Which bond has the highest bond energy? a. C – C b. C = C c. C ≡ C d. All of these bonds have the same bond energy 12. Which bond has the longest bond length? a. C – C b. C = C c. C=N d. H–H 13. Arrange the following three ionic compounds MgCl2, NaCl and MgO in order of increasing ionic bond strength. a. MgCl2 < NaCl < MgO b. MgCl2 < MgO < NaCl c. NaCl < MgCl2 < MgO d. NaCl < MgO < MgCl2 e. MgO < MgCl2 < NaCl Questions 14‐15 refer to these structures: The atoms are C, H, and F. The F is noted. H is small. 14. Structures A and D are: a. not related b. isomers c. conformations b. isomers c. conformations 15. Structures B and C are: a. not related 16. How many sigma and pi bonds does this structure have? a. 6 sigma + 2 pi b. 12 sigma + 2 pi c. 10 sigma + 4 pi d. 18 sigma + 0 pi e. 14 sigma + 4 pi 17. What is the formal charge on the left hand carbon atom in this structure? a. +2 b. +1 c. 0
d. ‐1 e. ‐2
18. Which of the following orbital subshells cannot exist in an atom? a) 5s b) 3f c) 4d d) 14s e) 4p 19. If an orbital has the wave function: ψ
have? 2
= 52∙y2∙e‐r which of the following orbital shapes will it 20. How many planar and how many spherical nodes does orbital #4 above have? 21. 22. 23. 24. b) one and one e) two and one c) one and two a) Sr2+ b) Rb+ c) Kr d) Br‐ e) Se2‐ Which of the following has the largest atomic size? a) Na b) K c) Mg d) Ca e) P Which of these has the highest ionization energy? a) Na b) K c) B d)C e) N Which of the following correctly describes the trends in the energies of the highest occupied orbitals of the elements in terms of the periodic table? “Across” means left to right. a. energy increases down a group and increases across a period b. energy decreases down a group and increases across a period c. energy decreases down a group and decreases across a period d. energy increases down a group and decreases across a period Why does covalent bonding occur? a) electrons are more stable when paired b) electrons from one atom are attracted to the nucleus of the other atom c) electrons want to fill an octet d) electrons on one atom are attracted to the electrons on the other atom 26. Which of the followping is largest? 25. a) none and none d) two and none How many valence electrons does a P atom have? a) none b) 8 c) 3 d) 4 e) 5