CHEM Come to the PASS workshop with your mock exam complete. During the workshop you can work with other students to review your work.

Transcription

1 It is most beneficial to you to write this mock midterm UNDER EXAM CONDITIONS. This means: Complete the midterm in 1.5 hours. Work on your own. Keep your notes and textbook closed. Attempt every question. After the time limit, go back over your work with a different colour or on a separate piece of paper and try to do the questions you are unsure of. Record your ideas in the margins to remind yourself of what you were thinking when you take it up at PASS. The purpose of this mock exam is to give you practice answering questions in a timed setting and to help you to gauge which aspects of the course content you know well and which are in need of further development and review. Use this mock exam as a learning tool in preparing for the actual exam. Please note: Come to the PASS workshop with your mock exam complete. During the workshop you can work with other students to review your work. Often, there is not enough time to review the entire exam in the PASS workshop. Decide which questions you most want to review the Facilitator may ask students to vote on which questions they want to discuss in detail. Facilitators do not bring copies of the mock exam to the session. Please print out and complete the exam before you attend. Facilitators do not produce or distribute an answer key for mock exams. Facilitators help students to work together to compare and assess the answers they have. If you are not able to attend the PASS workshop, you can work alone or with others in the class. Good Luck writing the Mock Exam!! Date and location of mock midterm take-up: Wednesday November 16 th 2016 at 7:30 10:30pm in Azrieli Theatre (AT) 101 Note: There will be no regular workshops this week!

2 Part A. Answer each of the six questions with a few sentences or equations where necessary. (5 Marks Each) [5] 1. Explain the relationship between atomic radius and electronegativity. [5] 2. AFBAU predicts the ground state electronic configuration for Chromium to be 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 4. Is this correct, why or why not? Explain. [5] 3. List the six intermolecular forces in order of increasing strength, including their approximate magnitudes.

3 [5] 4. Why is hexane (C 6 14 ) not soluble in water? [5] 5. What is the difference between LUMO and OMO molecular orbitals? [5] 6. Based on formal charge, explain which of the following structures of N 2 O (A, B or C) is more likely to form.

4 Part B. Answer any three of the following four questions (B1, B2, B3, B4). If you answer all four, the best three answers will count. [20 Marks Each] Note: For the purpose of the PASS mock midterm, please answer all four. [20] B1. Predict the shapes, ideal bond angle(s) and the type of hybrid orbitals used by the central atom in the following molecules. (Wrong name = zero marks, no part marks!) [6] a) CF 3 - [6] b) PCl 5 [6] c) AsF 4 [2] d) Circle the following diagram that correctly represents the net dipole moment of 2 O. O O O

5 [20] B2. [15] a) Calculate the lattice energy (kj/mol) of MgCl (s) given the following: Energy of sublimation of Mg (s) : First ionization potential of Mg: Energy of dissociation of Cl 2(g) : Electron affinity of Cl: Energy of formation of MgCl (s) +150 kj/mol +738 kj/mol +243 kj/mol 349 kj/mol 15 kj/mol [5] b) Draw arrows to indicate the direction of the following trends on each periodic table: Electronegativity Atomic Radius Electron Affinity

6 [20] B3. Consider the following molecular orbital diagram of O 2. [2] a) Calculate the bond order of O 2. π 2p π 2p [2] b) Calculate the bond order of O 2 -. σ 2p [2] c) Calculate the bond order of O 2 +. σ 2s [4] d) State whether a), b), and c) are paramagnetic or diamagnetic. Why? σ 2s [4] e) Describe the relationship between bond order, bond energy, and bond length. [3] f) State und s Rule. [3] g) Briefly explain what a sigma bond is. ow many sigma bonds can a molecule contain?

7 [20] B4. [7] a) Refer to the phase diagram below of water to answer the following questions i) On the diagram above, label the following: Solid Phase Liquid Phase Gas Phase Triple Point Critical Point Super Critical Point ii) The normal melting point of water is C iii) The normal boiling point of water is C iv) The critical point of water is at C and atm v) The triple point of water is at C and atm [4] b) What are the four properties of liquids? Briefly define each of them.

8 [9] c) Titanium (Ti) metal crystallizes in a body-centred cubic (BCC) structure with an edge length of 331 pm. Calculate the radius of a titanium atom (in pm).

9 Li Na K Rb Cs Fr (223) IIA (2) 4 Be Mg Ca Sr Ba Ra (226) IIIB (3) 21 Sc Y La Ac (227) IVB (4) 22 Ti Zr f Rf (261) VB (5) 23 V Nb Ta Db (262) VIB (6) 24 Cr Mo W Sg (266) VIIB (7) 25 Mn Tc Re Bh (264) VIIIB (8) (9) (10) 26 Fe Ru Os s (269) 27 Co Rh Ir Mt (268) 28 Ni Pd Pt Ds (269) IB (11) 29 Cu Ag Au IB (12) 30 Zn Cd g IIIA (13) 5 B Al Ga In Tl IVA (14) 6 C Si Ge Sn Pb VA (15) 7 N P As Sb Bi VIA (16) 8 O S Se Te Po (209) VIIA (17) 9 F Cl Br I At (210) 2 e Ne Ar Kr Xe Rn (222) 58 Ce Th Pr Pa (231) 60 Nd U Pm (145) 93 Np (237) 62 Sm Pu (244) 63 Eu Am (243) 64 Gd Cm (247) 65 Tb Bk (247) 66 Dy Cf (251) 67 o Es (252) 68 Er Fm (257) 69 Tm Md (258) 70 Yb No (259) 71 Lu Lr (260) Midterm Friday November 18 th 2016, 6:30 8:30pm Midterm Content Textbook: Chapter 5 Chapter 6 Chapter 7 (omit 7.7) Chapter 8 Lectures: Atomic Energies and Periodicity 1-3 Overview of Bonding 1-2 Theories of Chemical Bonding 1-3 Effects of Intermolecular Forces 1-3 Remember that all equations/formulas need to be memorized!