What would the value for k be?

Question

the reaction is C3H6Cl2+3Br-==>C3H6+2Cl-+3Br-

which gives the following data:

trial 1

Initial concentration of C3H6Cl2(M)

0.080

Initial concentration of Br-(M)

0.080

instantaneous reaction rate (M/s)

0.116

trial 2

Initial concentration of C3H6Cl2(M)

0.160

Initial concentration of Br-(M)

0.080

instantaneous reaction rate (M/s)

0.232

trial 3

Initial concentration of C3H6Cl2(M)

0.160

Initial concentration of Br-(M)

0.160

instantaneous reaction rate (M/s)

0.232

Answer 1

C₃H₆Cl₂ + 3Br^- ==>C₃H₆ + 2Cl^- + 3Br^-

Comparing trial 1 and trial 2, we see that [C₃H₆Cl₂] has doubled and [Br-] remains constant. The rate doubles telling us the reaction is 1st order with respect to C₃H₆Cl₂

Comparing trials 2 and 3, we see that [Br-] is doubled and [C₃H₆Cl₂] remains constant. The rate remains constant telling us the reaction is zero order with respect to Br-

Thus we can right the rate law as rate = k [C₃H₆Cl₂]

Pick a rate and solve for k. We will choose the rate in trial 1 as 0.116 M/s

0.116 M/s = k[0.080 M]

k = 1.45 s^-1