MOCK MIDTERM 1 questions by NiceTime


                    PASS MOCK EXAM – FOR PRACTICE ONLY

Course: CHEM 1000                           Facilitator: Billy Boudreau
Dates and locations of mock exam take-up: Tues. 4:00-5:30 PA 240
                                                     Fri. 12:30-2:00 TB 431


It is most beneficial to you to write this mock midterm UNDER EXAM CONDITIONS. This

               • Complete the midterm in 1.5 hour(s).
               • 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 session with your mock exam complete. There, you can work with
       other students to review your work.

      Often, there is not enough time to review the entire exam in the PASS session. Decide
       which questions you most want to review – the facilitator may ask students to vote on
       which questions they want to discuss.

      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 session, you can work alone or with others in the

                                       GOOD LUCK!
                           CHEM 1000 A, V MOCK Midterm Test #1

Part A. Ans wer each question with a few sentences or equations where necessary. (5 Marks each)
1.     If one atom of 12 C weights exactly 12 amu, why is the atomic mass of carbon equal to
       12.011 g?

2.    Why do atomic light sources have only discreet frequencies?

3.    A p-orbital is shown below. An electron in this orbital occupies both lobes. How can the
      electron get from one lobe to the other if the node is a place where the electron can never


4.    The ground electronic configuration for copper (Cu) is predicted by AUFBAU to be
      [Ar] 4s2 3d9 . However, Cu actually has a different configuration. State what you think the
      actual configuration is, and state why it is different from what AUFBAU predicts.

5.    Explain how the ionization energy changes going from left to right across a period, and briefly
      explain why this happens.

6.    Which of LiF(s) and LiCl(s) has the larger lattice energy and why? Which of KF (s) and SrF2(s) has
      the larger lattice energy and why? (Mid-Year Exam 2002/2003 #2)
 Part B. Ans wer any two questions. If you answe r all three, the best two ans wers will count.
(20 marks each)
B1.    (a) Use VSEPR theory to predict the shape of the SF3 + ion.

(b) Which of CH2 Cl2 , CHCl3 and CCl4 are polar? (Mid-Year Exam 2002/2003 #5)

(c) Calculate the formal charge on the B atom in BF 3 and use this result to explain why the B atom
        does not follow the octet rule. (Mid-Year Exam 2002/2003 #5)

(d) Predict the formulas of compounds formed from: (Mid-term Test 1 2003/2004 #B3)
        (i)     Na and Se
        (ii)    Y with O

(e) Why is the ionization potential of Zn greater than those of its two neighbours, Cu and Ga? (Mid-
term Test 1 2003/2004 #B3)

(f) Which of As or Se has the larger atomic radius? Why? (Mid-term Test 1 2003/2004 #B3)

(g) Why is the second ionization potential of each element greater than the first? (Mid-term Test 1
2003/2004 #B3)

(h) Which of LiF or KBr would have the higher lattice energy? Why? (Mid-term Test 1 2003/2004
B2.     (a) We have used the Balmer-Rydberg equation to calculate the wavelength of photons
emitted by atoms falling from an upper to a lower energy state. However, if we shine photons onto a
sample of hydrogen, we can actually cause the electrons to jump to higher levels. The same equation
applies in such a case. Suppose the electron in a ground state (m=1) hydrogen atom absorbs a photon
having a wavelength of 97.20 nm. To what upper level does the electron move?

(b) What is the energy of the photons having a wavelength of 97.20 nm? Express in kJ mol -1 .

B3. Born Haber cycles were used to make the first reliable prediction of an electron affinity. Calculate
the electron affinity of fluorine (F) given the following data:
        Heat of sublimation of potassium:                      +90 kJ mol-1
        Ionization potential of potassium:                     +419 kJ mol-1
        Bond dissociation energy of fluorine (F 2 ):           +159 kJ mol-1
        Lattice energy of KF(s):                               +821 kJ mol-1
        Net energy of formation of KF (s) from K(s) and F2(g): -569 kJ mol-1

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