1. Chem 1310: Introduction to physical chemistry Part 2a: PSP chapter 13 Peter H.M. Budzelaar

2. PSP 13.1, p612 Reaction of CV + with NaOH, rate is 1.27*10 -6 mol L -1 s -1 when [CV + ] is 4.13*10 -5 mol/L. (a) Estimate how long will it take for [CV + ] to drop from 4.30*10 -5 mol/L to 3.96*10 -5 mol/L. (b) Can you use the same method for a drop to 0.43*10 -5 mol/L? Explain.

3. PSP 13.2, p613 H 2 (g) + I 2 (g)  2 HI (g) (a) Express rate of formation of HI in terms of rate of disappearance of H 2. (b) If the rate of disappearance of I 2 is 0.0037 mol L -1 s -1, what is the rate of formation of HI?

4. PSP 13.3, p618 (a) Can you determine complete rate law from data in table? (b) Assume rate does not depend on [OH - ]. What is the rate law? (c) Calculate rate constant for this law. (d) Calculate initial rate for [CV + ] = 0.00045 M. (e) What is rate when [CV + ] is half of initial value? [CV + ][OH - ]in. rate 4.3*10 -5 0.101.3*10 -6 2.2*10 -5 0.106.7*10 -7 1.1*10 -5 0.103.3*10 -7

5. PSP 13.4, p619 2 NO (g) + 2 H 2 (g)  N 2 (g) + 2 H 2 O (g) Rate = k[NO] 2 [H 2 ] (a) Order wrt NO? H 2 ? (b) Triple [NO], reduce [H 2 ] by factor 8. How much faster/slower?

6. PSP 13.5, p622 Using Table 13.1, determine order in [CV + ], rate constant.

7. Zeroth-order plot t (s)[CV + ] (mol/L) 0.05.00E-05 10.03.68E-05 20.02.71E-05 30.01.99E-05 40.01.46E-05 50.01.08E-05 60.07.93E-06 80.04.29E-06 100.02.32E-06 First-order plot t (s)ln [CV + ] 0.0-9.90 10.0-10.21 20.0-10.52 30.0-10.82 40.0-11.13 50.0-11.44 60.0-11.74 80.0-12.36 100.0-12.97 Second-order plot t (s)1/[CV + ] (L/mol) 0.02.00E+04 10.02.72E+04 20.03.69E+04 30.05.03E+04 40.06.85E+04 50.09.26E+04 60.01.26E+05 80.02.33E+05 100.04.31E+05 k =0.030703 -SLOPE(I7:I15,H7:H15)

8. PSP 13.6, p623 Insecticide decomposes with first-order rate constant 3.43*10 -2 d -1. How long before concentration drops to 0.1 of initial value?

9. PSP 13.7, p624 From Fig 13.3 determine time needed for [CV + ] to drop to ½ its initial value. Verify same time required for next drop to ¼ of initial value. From half-life, determine rate constant.

10. PSP 13.8, p631 For reaction A  B, E a = 24 kJ/mol. For reverse reaction, E a = 36 kJ/mol. Draw energy profile. Is the reaction exothermic or endothermic?

11. PSP 13.9, p634 Calculate rate constant for reaction of MeBr with I - at 75°C, using Table 13.3 etc.

12. PSP 13.10, p641 Proposed mechanism for N 2 H 4 synthesis: NH 3 (aq) + OCl - (aq)  NH 2 Cl (aq) + OH - (aq) (slow) NH 2 Cl (aq) + NH 3 (aq)  N 2 H 5 + (aq) + Cl - (aq) (fast) N 2 H 5 + (aq) + OH - (aq)  N 2 H 4 (aq) + H 2 O (l) (fast) (a) Write balanced overall equation (b) Rate-limiting step? (c) Intermediates? (d) Expected rate law?

13. PSP 13.11, p650 Which compound is most likely to be an effective drug for bacteria needing to metabolize p-aminobenzoic acid?