Question

Trial 1

Time	Trans	A=2-log %T	Ln(A)	1/A
1:57	19.0	0.721	-0.327	1.39
2:52	22.0	0.658	-0.419	1.52
3:51	24.5	0.611	-0.493	1.64
4:54	27.3	0.564	-0.573	1.77
5:53	29.7	0.527	-0.641	1.90
6:54	33.6	0.474	-0.747	2.11
7:55	36.2	0.441	-0.819	2.27
8:54	40.0	0.398	-0.921	2.51
9:52	40.5	0.393	-0.934	2.54
10:53	45.3	0.344	-1.07	2.91
11:58	47.7	0.321	-1.14	3.12
13:02	52.2	0.280	-1.27	3.57
14:02	55.3	0.257	-1.36	3.89
14:59	56.0	0.252	-1.38	3.97
15:59	59.4	0.226	-1.49	4.42
16:58	60.4	0.219	-1.52	4.57
18:00	65.2	0.186	-1.68	5.38
19:06	65.9	0.181	-1.71	5.52
20:03	68.8	0.162	-1.82	6.17

Trial 2

Time	Trans	A=2-log % T	Ln(A)	1/A
1:43	25.7	0.590	-0.528	1.69
2:48	30.2	0.520	-0.654	1.92
3:41	45.4	0.343	-1.07	2.92
4:46	43.8	0.358	-1.03	2.79
5:46	47.6	0.322	-1.13	3.11
6:47	50.5	0.297	-1.21	3.37
7:48	56.9	0.245	-1.41	4.08
8:48	61.4	0.212	-1.55	4.72
9:45	62.3	0.206	-1.58	4.85
10:49	66.8	0.175	-1.74	5.71
11:45	72.5	0.140	-1.97	7.14
12:45	71.6	0.145	-1.93	6.90
13:45	76.5	0.116	-2.15	8.62
14:44	78.5	0.105	-2.25	9.52
15:42	83.1	0.080	-2.53	12.5
16:45	83.2	0.080	-2.53	12.5
17:43	88.4	0.054	-2.92	18.5
18:49	90.7	0.042	-3.17	23.8
19:42	84.5	0.073	-2.62	13.7
20:43	89.6	0.048	-3.04	20.8

Trial 1 added 10 ml 0.020 M of NaOH and 10 ml 1.5x10^-5 crystal violet

Trial 2 added 10 ml 0.040 M of NaOH and 10 ml 1.5x10^-5 crystal violet

tested the absorbance of solution for 20 minutes

1. Based on your experimental determined rate law for the reaction of crystal violet and hydroxide ion, how would doubling the concentration of crystal violet affect the reaction rate?

2. Would you have determened an identical rate law for the reaction of crystal violet and hydroxide ion if you had used hydroxide ion concentrations of 0.030 M and 0.050 M instead of 0.020 M and 0.040 M? briefly explain

3.The rate law for a certain reaction is second order with respect to one of the reactants, R. Suppose you study this reaction, observing the absorbance of light at the analytical wavelength for R, and record the data with respect to elapsed time. Also suppose that the concentrations of all the other reactants are in large excess, and that R is the only colored species invilved. Explain which absorbance function, A, LnA, or 1/A, would yeild a straight-line graph when plotted against elapsed time.

4. Suppose that in the reaction Q + R --> P, only the product is colored

b. what happens to the absorbance at the analytical wavelength for P of the mixture as the reaction progresses?

c. Suppose you do an experie=ment involving this reaction in which Q is present in large excess of R. If the reaction is first order whith respect to R, would the grapph of LnA (for P) versus time be a straight line? Briefly explain

Answer 1

Trial 1:

If reaction is zero order then graph :

If reaction is first order then graph:

If reaction is second order then:

So compare hese three graphs and R² value .

So R² value of first order graph is 0.998=1 so the reaction is first order.

Trial 2:

I think your trial 2 data is not appropriate.

If reaction is zero order then graph :

If reaction is first order then graph :

If reaction is second order then graph :