Question

Problem 1: chemical kinetics (5 points) Consider the method of initial rates for the hypothetical reaction 2R, + R2 -- P IRilo. M IR2lo. M Rate, M/s 0.1 1 2 0.1 2 2 0.4 1. Write down the rate equation for this reaction, indicating the orders of reaction with respect to species Ri and R2 (2 points). 2. Determine the numerical value of the rate constant k (0.75 points). 3. What are the units (if any) of rate constant k? (0.5 points) 4. What is initial rate (in M/s) when [R1]o = 3M and [R2lo = 10 M? (1 point) 5. What is the rate (in M/s) when [R1] = 0 M? (0.25 points) 6. If the formation rate of P is 0.1 M/s, at what rate R dissapears? (0.5 points)

Answer 1

d[p] - Rate of formation of p dt sol olan -10[R] i dt o d[P] at f shor dt dt molt = 2x01 MIS = 0.2Nls I at I lower pot ston 30 Golostno) i o d tro 0 2909 po Svodombo Scanned with CamScanner

kilo. M[R210, M Rate, Mls 01 20.1 1 d 2 014 QR + R2 p (1) Rate of a Reaction is defined as Product of concentration of reaction raised to the Powder order of the reaction worot to each reaction For the eq a rate = K[R] [22] r = K[R,]" [Ra] R = Reactant R2 = Reactant k= Rate constant rate of the reaction. = order of the reaction w.rit Ri m= Order of the reaction co.sot Ra Let us consider the data given in above table 8 = K[1]" [ 17h 0.1= K (1Jh [1— (19)

0.1 = x [1]"[a7m - (1) 0.4 = k [a" (a] (n) down Divide eq (1) by (118) at Kohtaj" 2011 *[1] [1] m ol 02": 1 , "C (2)+(1) m=0 with change in concentration rate of reaction do not changes so Orden wert R2 is equal to o. By Using Hit and trial method for the & Q11) and (10) equation for [R2] cond is constant and when we changes the cone of Ri rate is become a times. → It means. Ro Orden with respect to Ri i's 2. T oni for R. order = oogloon for R2 order = 2 jun

Now Rate equation in = K[R] ² [R210 / m=o Qu-2. Value of Rate constant stre 8= K[R] [R] Lejas na IoT 8 = K[R]" (v) foarom equation (11) we can write 0.1= K[1] (VD) ) nonost k = 10.1 aliwe rate constant = 0.1 mollls' Tupi obro Que-3. * Units for rate constant ride Unit for creo en rate = mol Lls! olmoitopo ( , for the sate equate on new bro 672God ishon Nak[R]*[kg] mollista k [mol L 17 K= mol Lt's solo s ro) 1 mola L.Qaroo k = mol-mo12[-1. 22.51 [K = molls 1). Scanned with CamScanner

14 gnitial Rate when [R] = 3 N and [R.]. = 10M 8 = K[R, J² [R21° -10 ka rate constant = ol [R]3 34 [R2] = 10M Date = 0.1(37° [10] ° = 0.19 rate = 0.9 mol Lyst Que-5 rate will be Leuo with concentration of R becomes o. 8= K[R, JO [R]° from above j & [ 2 ] ² equation Que-6 from the given equation QR, + R2 dp rate of reaction - Id[Ri] = a[2] = dp 2 dt at de _d[8] - Rate of disappearance of R, CS Scanned with d[R] . Rate of disappecuence of Rul dt CamScanner dt