Question

A student studied the clock reaction described in this experiment. She set up Reaction Mixture 2 by mixing 20 mL 0.010 M KI, 10 mL .001 M Na₂S₂O₃, 10 mL .040 M KBrO₃, and 10 mL 0.10 M HCl using the procedure given. It took 45 seconds for the color to turn to blue.

a. She found the concentration of each reactant in the reacting mixture by realizing that the number of moles of each reactant did not change when that reactant was mixed with the others, but that its concentration did. For any reactant A,

no. moles A=M_{A Stock} x V_Stock=M _{A Mixture}x V _Mixture

The volume of the mixture was 50 mL. Revising the above equation, she obtained

M _{A Mixture}= M _{A stock}X (V_Stock (mL))/ 50 mL

Find the concentrations of each reactant by using the above equation.
(I^-)__________ M; (BrO₃^-) _____________M; (H⁺) ____________M

b. what is the relative rate of the reaction (1000/t)? _________________

c. Knowing the relative rate of the reaction for mixture 2 and the concentrations of I^-, BrO₃^-, and H⁺ in that mixture, she was able to set up equation 5 for the relative rate of the reaction, The only quantities that remained unknown were k,m,n, and p. Set up Equation 5 as she did, presuming she did it properly.

2. For reaction Mixture 1 the student found that 85 seconds were required. On dividing Equation 5 for Reaction Mixture 1 by Equation 5 for Reaction Mixture 2, and after canceling out the common terms (k, terms in (BrO₃^-) and (H⁺)), she got the following equation,

11.8/22=(.oo2o/.0040)^m= (1/2)^m

recongnizing that 11.8/22 is about equal to 1/2, she obtained an approximate value for m. What is that value?    m=_________________

By taking logarithms of both sides of the equation, she got an exact value for m. What was that value?
m=_________________

Since orders of reactions are often integers, she reported her approximate value as the order if the reaction with respect to I^-

Answer 1

Answen in pagen According to the given information, b find the following problems. Given, the sweaction mixture & by mixing. Mixtenie az, 20mL o. OOM KR loma 0.001M Na2S2O3 cond O OLOM KBNO, 10md O0IOH Hd. Total volume a somil. time, + 45 sec @ find the concentration: According to problem, number of moles A = MAStock X Vstocks = MA mixture x Umixture Lol, Mamixture Maistock x Vstocke (ma] Total valume. MI-] = 0.010m Ⓡ 2012 50ml | MCI }= 0.00uoM)

н(B505 ) . Осцон х 10ml page @ 50ml M( BR103) - 0.0080M M(H+) : 0.10M X lonel soma MCH+] = 0.020M o relative rate of the waellon: exchat is Gquen, coolt - 1000lus sec 2 22. 22 sec © find relative Rate of the reaction : knowing the rulative owale of the suaction bor mixture & and the concentration of 2*, Balog", Ht in - that mixture, Equation is) for the relative rate of the Oreaction can be set up Hence, es Relative sate : k[-1[enos) "CH+]P @ bet, for preaction mixtures the student found the 85 seconds were grequired. pfuinq. Equation s foor reaction mixtemel

by equations for creaction mixture a and canceling! page out the common tume (K, tum, in (Brogl/4+IP): NOW, mortevie != 1000/65 Seconds. the equation is 118 - 10:0020 m 22 loooouo 23 Its • )m. * Recong niting. that 11.8122 PS equal to 119. ma? here - 0.936 – Ya met * By taking logarithm. . logy (1) toggle (the .. ma logra levit)