Along the lines of rate laws come half-lives. Such a common topic that comes to mind with half-lives is the decay of radioactive elements, or the time it takes for a certain sample of an element to reach half of its original size. For example, during the Chernobyl power plant incident in 1986, one of the most dangerous elements to begin its decay was Cesium-137 which has a half-life of 30 years. Therefore, people can’t move back to the area because of the deadly amounts of Cesium-137 still present. (Chernobylgallery. com) In the context of the lab, the half-life was how much time it took for the Absorbency to become half its original value. In other words, when the [Fe(Phen)3]2+ dissociated half way, it reached its half-life. The reaction for
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A rate law is an equation used to determine how much the concentrations of solutions will change as times goes on. In this experiment, the rate changed based on the five degree Celsius temperature change and concentration change in three different reactions. In this lab, temperature had a drastic effect on the rate of the reaction. In the third trial, increasing the temperature only by five degrees Celsius increased the rate of reaction by a substantial amount. This was determined because less time was needed for ferroin to reach a absorbance of less than 0.05. However, concentration didn’t have much of an effect on the rate of reaction. This was because the reaction was zero order for the concentration of [Fe(Phen)3]2+, meaning that changing its concentration would have no impact on the overall reaction rate. This is the general rate …show more content…
The procedure for finding this value came from using the zero order integrated rate law for trials one and two. It was carried out this way because the reordered Arrhenius equation used needed two k values, one from each integrated rate law. These values were plugged into the Arrhenius equation, which also used the corresponding temperatures from the reaction values used.
One of the likely errors that occurred was placing the solutions into the colorimeter too late to measure an accurate absorbency before placing it into the water bath. The lab instructed the experimenter to take the first absorbency measurement at time 0, but time, though a small amount, passed between mixing the solution and the first reading. Therefore, the data was not accurate at this particular time because the reaction already began when the first absorbency measurement was
A rate law is an equation used to determine how much the concentrations of solutions will change as times goes on. In this experiment, the rate changed based on the five degree Celsius temperature change and concentration change in three different reactions. In this lab, temperature had a drastic effect on the rate of the reaction. In the third trial, increasing the temperature only by five degrees Celsius increased the rate of reaction by a substantial amount. This was determined because less time was needed for ferroin to reach a absorbance of less than 0.05. However, concentration didn’t have much of an effect on the rate of reaction. This was because the reaction was zero order for the concentration of [Fe(Phen)3]2+, meaning that changing its concentration would have no impact on the overall reaction rate. This is the general rate …show more content…
The procedure for finding this value came from using the zero order integrated rate law for trials one and two. It was carried out this way because the reordered Arrhenius equation used needed two k values, one from each integrated rate law. These values were plugged into the Arrhenius equation, which also used the corresponding temperatures from the reaction values used.
One of the likely errors that occurred was placing the solutions into the colorimeter too late to measure an accurate absorbency before placing it into the water bath. The lab instructed the experimenter to take the first absorbency measurement at time 0, but time, though a small amount, passed between mixing the solution and the first reading. Therefore, the data was not accurate at this particular time because the reaction already began when the first absorbency measurement was