Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

consider the following reaction CHCl 3 (g) + Cl 2 (g) ----> CCl 4 (g) + HCl (g)

ID: 691717 • Letter: C

Question

consider the following reaction CHCl3 (g) +Cl2 (g) ----> CCl4 (g) + HCl (g)

initial rate of the reaction was measured at several differentconcentrations of the reactants with the following results
[CHCL3] (M)       [Cl2] (M)       Initial rate (M/s)
.010                         .010                 .0035
.020                         .010                  .0069
.020                         .020                  .0098
.040                         .040                   .027

Determine the rate law for the reaction and the rate contant (k)for the reaction.

please show me steps.

I know the answer is k[CHCl3][Cl2]1/2

(k) = 3.5 M ^ -1/2 * s^-1

but how..




Explanation / Answer

1. Get rate for each reactant

Rate2/Rate1 = k[CHCl3]^(n/2)/k[CHCl3]^(n/1)

(0.0069M/s)/(0.0035M/s) = k(0.20M)^n/k(0.10M)^n

2 = (0.20/0.10)^n

2 = 2^n

log 2 = log (2^n)

log 2 = n log 2

n = log2/log2

n = 1

Do the same for Cl2 using rate where the concentration is changing not staying the same and you will get n = 0.5.

2. Insert rates into rate law

Rate = k [CHCl3]^1[Cl2]^0.5

= k [CHCl3][Cl2]^0.5

3. Find k, use any rate and the corresponding concentrations

k = rate/[CHCl3][Cl2]^0.5

= (0.0035 M/s)/ (0.010M)(0.010^0.5M^0.5)

= (0.0035 M/s)/ (0.010M)(0.10M^0.5)

= (0.0035 M/s) / (0.001 M^1.5)

= 3.5 M^-0.5 s^-1