Purpose: To determine the kinetics of the acid-catalyzed reaction of bromine and acetone via initial rate measurements and isolation method in order to approach the reaction mechanism.
Data and discussion: The initial reaction of the production of brominated acetone can be written as:
CH3COCH3 (aq)+ Br2 (aq) ---→CH3COCH2Br(aq) + Br– (aq) + H+ (aq)

Data table Trial | Saturated Br2 solution (mL) | Acetone(mL) | 1.00 M HCl(mL) | Initial rate(abs/min) | [Ac](M) | [HCl](M) | Mole/L Br2 reacting per min per liter | Rate constant(M-1 min-1) | 1 | 3 | 5 | 10 | 0.0060 | 0.681 | 0.1 | 1.11 E-4 | 1.72 E-3 | 2 | 6 | 5 | 10 | 0.0060 | 0.681 | 0.1 | 1.17 E-4 | 1.72 E-3 | 3 | 9 | 5 | 10 | 0.0120 | 0.681 | 0.1 | 1.59 E-4 | 2.33 E-3 | 4 | 9 | 5 | 5 | 0.0120 | 0.681 | 0.05 | 1.60 E-4 | 2.33 E-3 | 5 | 9 | 5 | 20 | 0.0240 | 0.681 | 0.2 | 3.01 E-4 | 4.57 E-3 | 6 | 9 | 10 | 20 | 0.0480 | 1.362 | 0.2 | 6.23 E-4 | 1.10 E-3 | 7 | 9 | 20 | 20 | 0.0900 | 2.742 | 0.2 | 1.79 E-4 | 3.22 E-3 |

The concentration of the saturated bromine solution was determined by diluting and measuring the absorbance of the solution at 450 nm .Distilled water was used as blank. The Beer’s law was then used to determine the concentration of bromine solution.
Abs =ЄCl
Where, Abs=0.288 and l= 1 cm and Є is the extinction coefficient or molar absorption coefficient = 100 (M-1 cm-1). So concentration of bromine solution was calculated using 1:100 dilution. To determine the initial rate, Abs vs. time (second) was plotted for all seven runs. The mechanism was evaluated by comparing the experimentally observed rate law to the theoretical rate law that is derived from the mechanism. The forms of the rate law were supported to the mechanism(Explain what do they mean).The experimental rate was calculated using:
Rate = k [Ac] [H+]
Concentration of acetone is doubled from run # 5 to #6 (.681M to 1.362M) and the initial rate is also doubled (0.0240 to 0.0480 abs/min) .Therefore the reaction must be first order in acetone. The concentration of HCl also doubled from run #3 to #5 (0.1M to 0.2M) so as the initial rate has doubled (0.0120 to 0.0240 abs/min) which conform that reaction is following the first order in HCl. The literature value for the rate constant at 250C was = 1.7 × 10-3 M-1 min-1 and was compared to experimental value = 2.4 × 10-3 M-1 min-1. The percent error was calculated to 41.1%. The timing of the reaction was very important for obtaining good data( How so???). Since the reaction would begin as soon as the bromine comes in contact with the acetone. In some runs bromine was added before HCl and acetone which has created error during this experiment.

Put caption for all the plots.
Why the value of rate constant differ so much. Average value of the rate constant and std. dev