Chapter 7, Problem 40P

Use the reaction coordinate diagram to answer the below questions. Type your answers into the answer box for each question. (Watch your spelling) Energy A B C D Reaction coordinate E A) Is the reaction step going from D to F endothermic or exothermic? A F G B) Does point D represent a reactant, product, intermediate or transition state? A/ C) Which step (step 1 or step 2) is the rate determining step? A

1. Using radii from Resource section 1 (p.901) and Born-Lande equation, calculate the lattice energy for PbS, which crystallizes in the NaCl structure. Then, use the Born-Haber cycle to obtain the value of lattice energy for PbS. You will need the following data following data: AH Pb(g) = 196 kJ/mol; AHƒ PbS = −98 kJ/mol; electron affinities for S(g)→S¯(g) is -201 kJ/mol; S¯(g) (g) is 640kJ/mol. Ionization energies for Pb are listed in Resource section 2, p.903. Remember that enthalpies of formation are calculated beginning with the elements in their standard states (S8 for sulfur). The formation of S2, AHF: S2 (g) = 535 kJ/mol. Compare the two values, and explain the difference. (8 points)

In the answer box, type the number of maximum stereoisomers possible for the following compound. A H H COH OH = H C Br H.C OH CH

7. Magnesium is found in nature in the form of carbonates and sulfates. One of the major natural sources of zinc is zinc blende (ZnS). Use relevant concepts of acid-base theory to explain this combination of cations and anions in these minerals. (2 points)

6. AlF3 is insoluble in liquid HF but dissolves if NaF is present. When BF3 is added to the solution, AlF3 precipitates. Write out chemical processes and explain them using the principles of Lewis acid-base theory. (6 points)

5. Zinc oxide is amphoteric. Write out chemical reactions for dissolution of ZnO in HCl(aq) and in NaOH(aq). (3 points)

Draw the product(s) formed when alkene A is reacted with ozone, followed by Zn and H₂O. If no second product is formed, do not draw a structure in the second box. Higher Molecular Weight Product A Lower Molecular Weight Product draw structure ... draw structure ...