Question

7. The decomposition of bromodichloroacetate BrCl2CCO2 is an important required step in water purification. The kinetics of such decomposition has been presented in Chemical Reviews, November 2001. There are two possible pathways for these reactions, one unimolecular and the other bimolecular with the help of OH" ions. Path 1. BrCl,CCO2 + H2O → CHCl Br + HCO3 With a pseudo-first order rate constant kı=1.6 x 10-6 1/sec Path 2. BrCl,CC02 + OH → Cl2OHCCO2 + Br With a second order rate constant k2=2.4x104 1/(M sec) a. Write the overall rate law for the disappearance of BrCl2CCO2 b. What is the ratio of the rates for paths 1 and 2 at pH=7? C. At what pH would the rate for path 2 be 10% of the rate for path 1?

Answer 1

overall so overall rate a) law for disappearance of { exce co; ) e at path I * -d[Bialyc.com), ki [Bralyc.com] lue] Hao is in bulk :. [1₂0] 21 -d C Bral, cloi) K [Bre, i cos] olt = 1.6.10 (Bracco Mst! for patt 2 - d[Br Cl CCOZ] K (Brce, co] (or). - d[ Br Cl₂ ccor] 2.4 104 [Brecco) soli Mst. de at to 10 for path 122 NOEN = HOG 6) Ration of rate (a (Bicla (cow/at pathl {a(druccolat) paths = o x 106 [Brutto lust 4XL0Y3ight tol.com) COH-] at pH=7 - ot pot is also a ' - log Lore] 70 = [Ort] = 107

path I path 2 10-7 xlos path I puth 2 ni.. Cool werd I b soln, we found that ( from above path I pathe path 2 2 - .3 in 102 COH 10% of . path) sous lord 3 b. 3. » Path 2 = 0.1 path L ophtpol = 14 рои = Tч-ри Vaudia-log [on) - 14-pH, 2001050. - Nalos wat [06)= 10 (hu) . - put u inain equation, Ho3 path I 0.1 pathl X 10-2 WIN lo (ph-14)

-phtly 1o * 2012-ph 15 - e le l2-24 lo both sides Take 2 = 12-ph 10.8 RH =